TAMM, Circuit Judge:
We are summoned in this case to review the award of summary judgment against a federal civil-service employee dismissed from her job on grounds of mental disability.1 We vacate that judgment and remand the case to the district court for a determination of whether a certain provision of the Civil Service Commission’s Federal Personnel Manual is a regulation binding upon the employing agency, and if found to be such, for a further determination of whether the agency substantially complied with it.
I
Our pseudonymous appellant formerly was employed as a clerk-typist, GS-3, in the Office of Research and Technical Services (ORTS), Bureau of Engraving and Printing (Bureau or agency), Department of the Treasury. Hired by the Bureau in June of 1971, appellant came to her new job with two years of prior federal employment and thus enjoyed civil-service protection as a non-probationary federal employee. For her first few months with the Bureau, appellant performed her duties without apparent difficulty. In October 1971, for in-[268]*268stance, she received a descriptive performance evaluation of “well qualified” with a near-perfect performance requirement record.2 Record 70. Some months later, however, she began to exhibit an emotional instability which thereafter required several lengthy absences for hospitalization3 and, the agency claims, frequently disrupted office routine and reduced her job effectiveness.
When these problems continued with only occasional surcease, the agency, in March 1973, directed appellant to undergo a fitness-for-duty examination4 in order to ascertain her suitability for continued employment.5 Appellant agreed to have this examination, and, after a general physical examination the day before by a Dr. Tre-mols, she underwent a one-time, 45-minute psychiatric examination conducted by a Dr. Calixto Valle, III, on April 17, 1973. Dr. Valle, who never had occasion to reexamine appellant, diagnosed her condition as “schizophrenia, chronic-undifferentiated, compensated” and concluded that she was “not fit for duty at this time.” Dr. Valle’s medical [269]*269opinion consisted only of these two above-quoted conclusions, jotted down at the bottom of the official examination form. Id. 48-50. This unelaborated medical “impression” was then incorporated into a report which, in turn, was “concurred in” by the Bureau’s own Health Unit physician, Dr. N. V. Scorzelli.6 Id. 100.
The Bureau finally notified appellant that it was seeking her removal and placing her in leave-without-pay status pending conclusion of separation proceedings within the agency. Her removal notice reiterated the allegations set forth in the earlier fitness-for-duty examination directive, see note 4 supra, and added further:
Because of your periodic disruptive behavior which causes undue problems to the small staff of this office and creates confusion in the work area, I [the Chief, ORTS] directed you to take a fitness-for-duty examination by letter of March 12, 1973. This letter states specifics of your erratic behavior and is attached as a part of this notice of proposed removal. You elected to have this examination conducted by the Public Health Service and named your sister ... to represent you to see that your rights w.ere protected.
In a memorandum dated May 18, 1973, Dr. N. V. Scorzelli, Medical Officer in charge of the Health Unit of this Bureau, informed [the] . . . Chief, Office of Industrial Relations, that he had received from the United States Public Health Service Outpatient Clinic results of the fitness-for-duty examination conducted in your case. The examination was conducted by Dr. Jose G. Tremols [sic] [Dr. Valle] whose diagnostic conclusion was “that due to your mental condition you are not fit for duty at this time.” Dr. Scorzelli advised that this is a chronic condition and he concurs with these findings. (You are not eligible for disability retirement inasmuch as you do not have five years of Federal Service.).
Record 94.
Appellant responded to this notice orally and in writing. Her written communication transmitted a mental status and employment capacities report, prepared at appellant’s request by another Public Health Service psychiatrist, Dr. F. Wm. Bernet, which prognosticated that “with continued therapy and medication [appellant] will be employable” and recommended that she be permitted to return to her job at the Bureau. Id. 84, 86. Soon after receiving this report, the Bureau Head of the Employee Relations Branch met with Dr. Scorzelli and his nursing assistant and agreed to proceed with the removal proceedings since, notwithstanding Dr. Bernet’s favorable conclusion,7 “it was the consensus of opinion that, inasmuch as [appellant’s] condition is chronic, there would be no lasting improvement . .” Id. 81. Appellant finally was separated from her agency on June 29, 1973, on grounds that she was not fit for duty and that her removal was necessary to promote the efficiency of the service.8 Id. 78-79.
Post-termination administrative appeal proceedings then commenced at her behest. See 5 C.F.R. Part 771 (1974). An adjudicatory hearing was held at the agency in September before an independent Appeals Examiner, during which both parties submitted evidence and introduced the testimony of various witnesses, Dr. Valle, the practicing psychiatrist, among them. The examiner subsequently recommended that the removal action be upheld as warranted by the evidence and in compliance with appli[270]*270cable procedural requirements, and this recommendation was adopted by the agency as its final decision in February 1974.
Appellant proceeded then to the next stage of her available administrative remedies, see id. Part 772, by appealing the agency’s decision to the Civil Service Commission’s (Commission) Appeals Examining Office (AEO), which ultimately sustained the decision as reasonable and procedurally sound. The AEO chose not to confine its review to the existing record, however, as counsel for appellant apparently had anticipated. Compare Record 26 with id. 120. Instead, it sought and received the additional medical opinion of a Dr. Eck, Chief of the Bureau of Retirement, Insurance and Occupational Health’s Medical Division, on the question whether “the observed deficiencies in [appellant’s] performance, outlined above, are attributable to her diagnosed disabling condition; and whether this condition would make the employee a hazard to herself or others.” Id. 25. Dr. Eck’s medical statement, which was later incorporated into the AEO’s affirmance, opined only that
the observed deficiencies and other actions are a result of her diagnosed mental illness. The psychiatric findings in the file9 reveal meager paranoid or hallucinatory elements, and for this reason could conclude that her condition is not a hazard to herself or others. However, suicide and homicide are of danger in schizophrenia, and it is a most difficult assessment to make as to the possibility or probability of their being a hazard to themselves or others.
Id. 23.
A final administrative appeal was then taken to the Commission’s Appeals Review Board (ARB)10 which affirmed the AEO’s decision, concluding that the AEO’s action in submitting appellant’s case file to Dr. Eck for an additional medical opinion had been proper and that the AEO’s decision had been an independent one based on its reasonable evaluation of the record evidence.
With her administrative remedies finally exhausted, see 5 C.F.R. § 772.307(c) (1974), appellant brought suit in the district court seeking the usual declaratory, injunctive, and compensatory relief. This proved unavailing, however, for the trial judge granted the Government’s motion for summary judgment upon consideration of the pleadings, cross-motions for summary judgment, and the administrative record. Undeterred, appellant has followed the usual course in availing herself of a duplicative appeal to this court,11 arguing once again that the agency failed to comply with applicable personnel regulations, that its decision was arbitrary and irrational, and that the AEO’s communication with Dr. Eck denied appellant the due process to which she was entitled.
[271]*271II
In passing upon appellant’s claims, we must remain cognizant of. the confines of our review. While the transition from unreviewability12 to reviewability of adverse personnel actions against federal employees has left a legacy of some disagreement and confusion in the reported cases, it is at least reasonably well-settled that, whatever its exact scope, judicial review in the federal courts is’ necessarily limited. Federal judges do not sit as ombudsmen for government employment relations,13 nor do we indulge the conceit of substituting our own judgment ad libitum for that of the agency.14 Rather, we concern ourselves in the personnel business only insofar as is necessary to assure that the action challenged (1) is not arbitrary or capricious;15 [272]*272(2) was reached in conformity with relevant procedural requirements;16 and (3) was not otherwise unconstitutional.17
Our review, as that of the district court before us, is limited to scrutinizing the administrative record accreted as the adverse action proceeds along its tortuous course up through the various levels of appeal. No de novo hearing is held,18 and, in this particular case, at least our review of the record is undertaken with the ultimate aim of determining whether the Government was entitled to its summary judgment as a matter of law, the parties having in effect agreed during the proceedings below that there were no factual issues outside of the certified record. See Fed.R.Civ.P. 56(c); Bouchard v. Washington, 168 U.S. App.D.C. 402, 405, 514 F.2d 824, 827 (1975).
Ill
A
Appellant first argues that the Bureau failed to establish any rational connection between the medical conclusions of Dr. Valle and the observed deficiencies asserted as grounds justifying appellant’s removal. Appellant’s Brief at 23-26. The AEO and ARB both concluded that the requisite causal link had been satisfactorily established, and we agree.
In law as well as logic, there must be a clear and direct relationship demonstrated between the articulated grounds for an adverse personnel action and either the employee’s ability to accomplish his or her duties satisfactorily or some other legitimate governmental interest promoting the “efficiency of the service.”19 Absent a nexus between the “cause” asserted — here mental disability — and “promotion of the efficiency of the service,” the adverse action must be condemned as arbitrary and capricious for want of a discernible rational basis.20 See e. g., Norton v. Macy, 135 U.S.App.D.C. 214, 220, 417 F.2d 1161, 1167 (1969) (alleged homosexual advance); Scott v. Macy, 121 U.S.App.D.C. 205, 208, 349 [273]*273F.2d 182, 185 (1965) (“immoral” conduct must be shown to be “related to ‘occupational competence or fitness’ ”); Mindel v. United States Civil Service Commission, 312 F.Supp. 485 (N.D.Cal.1970) (meretricious romance). See generally Gayer v. Schlesinger, 160 U.S.App.D.C. 172, 180, 183, 490 F.2d 740, 748-51 (1973) (homosexuality).
This so-called nexus requirement is articulated with varying degrees of particularity throughout the laws, regulations, and policies governing the civil service system.21 Most generally, for example, an adverse personnel action may not be taken against an employee.covered, as appellant was, by chapter 752 of the Federal Personnel Manual except for “such cause as will promote the efficiency of the service.” 752 FPM 1-3 (Apr. 1972); accord, Lloyd-LaFollette Act § 6(a), codified at 5 U.S.C. § 7501(a) (1970); 5 C.F.R. § 752.104(a) (1974). This standard — a leitmotif throughout federal personnel administration — -is refined by the Manual when it further delimits to certain specified employment concerns:
A just and substantial cause is necessary as a basis for an adverse action and the action must be determined on the merits of each individual case.
752 FPM 1-3 (Apr. 1972). Finally, and most precisely to the point of our present case, the Manual clarifies that a mental or physical disability indeed may warrant removal under the procedures established by chapter 752, but specifically requires that in undertaking such medical disability proceedings an agency must link the disability to certain specified employment concerns:
The agency must not rely solely upon a showing that the employee has a disabling condition, even when the agency has obtained a medical opinion of incapacity. Neither the placement of limitations on the duties which an employee is permitted to perform nor medical conclusions about the employee’s physical condition is sufficient cause for taking adverse action. The agency must establish a link between the medical conclusion and (i) observed deficiencies in work performance or employee behavior or (ii) high probability of hazard when the disabling condition may result in injury to the employee or others because of the kind of work the employee does. When an agency can clearly show high probability of serious hazard — for example, an agency has indisputable evidence that a truck driver with epilepsy is subject to grand mal seizures — the agency does not have to wait for the employee to have a serious accident on the job before taking adverse action. The medical evidence linked with the showing of potential hazard would be sufficient cause for taking adverse action. In all other cases, however, the agency must link the medical conclusion with observed deficiencies in work performance or employee behavior.
752-1 FPM S1-3a(5)(f) (Feb. 1972) (emphasis added).
With the exception of the unparticularized assertion of Dr. Eck in his medical opinion to the AEO, there was not the slightest suggestion that appellant’s incapacity posed a “high probability of hazard . to [herself] or others because of the kind of work [she] does.” The Government does not argue to the contrary — as it reasonably could not on the basis of the present record — but contends rather than substantial evidence apart from Dr. Eck’s opinion clearly established the necessary causal link between the medical conclusion reached in the fitness-for-duty examination and appellant’s disruptive behavior and unsatisfactory job performance. Thus, it characterizes Dr. Eck’s opinion as “merely cumulative, rather than operative.” [274]*274Government’s Brief at 8 n.4. It is, then, to the so-called “operative” record evidence of observed work-related deficiencies that the agency must have linked the medical opinion of disability.
It is true, as government counsel conceded at oral argument, that the administrative record before us contains no precise and explicit nexus statement by the agency. Were we to require an employing agency to exclaim — “ecce nexus ” — whenever it sought to separate an employee on disability grounds, we perhaps might have reached a different result in this case. We refrain from imposing such a wooden, formalistic requirement on the agency, however, believing that it is enough to satisfy the Manual’s nexus requirement if the agency has furnished a rational basis in the evidence for its conclusion that a diagnosed medical problem has adversely affected the employee’s job-related behavior or performance. From our reading of the administrative record in the instant case, we think it rather obvious that appellant’s diagnosed medical problems at times did substantially and adversely affect her work performance and employment behavior. At other times, it is true, her psychiatric problems — to the extent they were of a continuing nature — did not manifest themselves in any negative, occupationally-related manner. Still, for what we consider a rather generous period of time, the Bureau did subordinate its legitimate interests in the efficient performance of its tasks22 and in maintaining a satisfactory level of office morale23 in order to accommodate and help ameliorate appellant’s unfortunate emotional problems.
We are not much impressed with counsel for appellant’s imaginative attempt to limit the signification of Dr. Valle’s psychiatric conclusion to nothing more than an immaterial datum of evidence that appellant was mentally “not fit for duty” only on the particular day of her psychiatric examination, so that the diagnosis could not theoretically be related to instances of “observed deficiencies” on any previous day.24 See Appellant’s Brief at 24-25. There is not, in fact, insofar as we have been able to determine, a requirement of any greater showing than was made by the Bureau here. While we are also not much impressed with the value of the psychiatric examination administered to appellant by Dr. Valle, see infra at 35-36, at least from what appears of it in [275]*275the record, the medical conclusion based upon that fitness-for-duty examination was indisputably one of mental disability and employment incapacity. The removal notice expressly incorporated the directive-to-undergo letter and the findings of the examination which, when taken together, were sufficient both to satisfy the requirement that the nature of the charges be complete and detailed, 5 U.S.C. § 7512(b)(1) (1970), and to establish the requisite link between the medical conclusion and the observed deficiencies noted in the directive to undergo the examination.
Confronted with another case, we might well require more than Dr. Valle’s terse, unelaborated medical conclusion that appellant was “not fit for duty at this time.” His examination, such as it may have been, however, is far from the only evidence of record underscoring appellant’s mental disability and its adverse effect on her value as a federal employee. Our careful review of the record in this case fortifies us in our conclusion that the agency’s decision, which the Commission subsequently approved was not so lacking in evidentiary support as to be condemned and set aside as arbitrary. See Dabney v. Freeman, 128 U.S.App.D.C. 166, 170, 358 F.2d 533, 537 (1965). See also Mendelson v. Macy, 123 U.S.App.D.C. 43, 47, 356 F.2d 796, 800 (1966).
For instance, we have before us, as did prior reviewing tribunals, uncontested evidence that during appellant’s two years with the Bureau she was absent from work due to psychiatric illness or its treatment for periods aggregating more than 92 days on 72 occasions.25 Record 61; see id. 55-64. These absences were in part attributable to continuing outpatient therapy at a unit of St. Elizabeth’s Hospital since January 1972, Record 84, an absence from work during the period January 7, 1972, to February 14, 1972, during which time she was treated at D.C. General and St. Elizabeth’s Hospitals, id. 115, and inpatient treatment at St. Elizabeth’s and convalescence from December 7, 1972, to January 5, 1973. Id. 84, 115.
The record also reveals that the Bureau expended considerable time and expense in attempting to accommodate her disability. During her tenure at the agency, for instance, nurses were summoned to care for her five times, she was brought to the Mental Health Clinic by co-workers four times, taken by Bureau car to St. Elizabeth’s Hospital 44 times, taken to George Washington Hospital by ambulance once, taken to the hospital by Bureau car three times, and sent home by Bureau car six times. Id. 59-60. Finally, we note that a doctor at St. Elizabeth’s had diagnosed appellant’s condition on January 13, 1972, as acute schizophrenia episode, and that the same diagnosis was made almost a year later, during her hospitalization from December 7, 1972, to January 2, 1973, after appellant apparently had stopped taking her prescribed medication. Id. 65.
In sum, then, we conclude that the findings of mental disability and the alleged instances of disruptive behavior are supported by sufficient evidence such that we may discern a rational basis for the Commission’s holding that the agency had adequately established that the observed deficiencies in appellant’s behavior at work stemmed from that diagnosed disability. As the AEO explained, id. 21, the agency’s letter directing appellant to undergo the fitness-for-duty examination set forth the specific instances of unsatisfactory behavior, see note 4 supra, upon which the agency [276]*276later relied in instituting the removal proceedings. With this information, appellant’s job description, and other personnel history before him, see id. 102-05, Dr. Valle psychiatrically concluded that she was not fit for duty at that time. This medical conclusion was incorporated into the notice of proposed adverse action, and by so doing the Bureau satisfied any nexus requirement. See generally 5 C.F.R. § 339.101 (1974); Salter v. United States, 412 F.2d 874, 875, 188 Ct.Cl. 524 (1969) (“If the medical report [fitness-for-duty examination] had established that plaintiff was physically or mentally unfit for his position, he could have been removed or demoted therefrom for this reason.”) At least in this case, any other conclusion would be unduly formalistic.
B
Appellant also argues quite forcefully that the communication between the AEO and Dr. Eck, characterized as an ex parte contact, amounted to a prejudicial violation of administrative due process. See Appellant’s Brief at 26-30; Appellant’s Reply Brief at 1-4. We agree, but only in part.
At the outset, it will be worthwhile to clarify what we consider not to be involved in this particular case. For one, we do not confront here, as the Court of Claims did in Camero v. United States, 375 F.2d 777, 779-81, 179 Ct.Cl. 520 (1967) and Jarett v. United States, 451 F.2d 623, 628-29, 195 Ct.Cl. 320 (1971) (where decisions adverse to government employees were reversed), ex parte communications of the employing agency concerning the merits of the case addressed to those responsible for decision in proceedings required by regulations to be adversarial evidentiary hearings. See, e. g., Gayer v. Schlesinger, supra, 490 F.2d at 747; Brown v. United States, 377 F.Supp. 530, 539 (N.D.Tex.1974) (procedural due process violated where hearing examiner on several occasions discussed case with “prosecutor” for agency prior to agency hearing). Nor is ours a case where the relevant factors and contentions in a controversy were not known to all of the parties. Cf. Moore-McCormack Lines, Inc. v. United States, 413 F.2d 568, 183 Ct.Cl. 644 (1969). Moreover, Dr. Eck was not allied with an adversary, and, absent some reason to believe otherwise, we should presume that he had a neutral stake in the outcome of the appeal.
Were it otherwise, this might be a different case, for, as a general rule, ex parte communications by an adversary party to a decision-maker in an adjudicatory proceeding are prohibited as fundamentally at variance with our conceptions of due process. See Sangamon Valley Television Corp. v. United States, 106 U.S.App.D.C. 30, 269 F.2d 221 (1959); Administrative Procedure Act § 5(c), 5 U.S.C. § 554(d) (1970). In short, whatever else it may have been, this alleged ex parte communication was not an unsolicited, self-serving contact initiated by an interested party to add to its factual evidence or to proffer further justification for its actions after the record should have been closed.
On the other hand, however, the AEO’s solicitation of an additional medical opinion is hardly analogous to “an assembling of the files and a placing of the case in proper posture for the hearing” which the Court of Claims found acceptable in Korman v. United States, 462 F.2d 1382, 1388, 199 Ct.Cl. 78 (1972), or, as the Government now urges, to the appropriate use of assistants underwritten by the Supreme Court in Morgan v. United States, 298 U.S. 468, 478-82, 56 S.Ct. 906, 80 L.Ed. 1288 (1936), and by this court in Braniff Airways, Inc. v. CAB, 126 U.S.App.D.C. 399, 407, 379 F.2d 453, 461 (1967). What occurred in this case must be viewed as essentially the introduction of further medical opinion evidence into the record, and not simply the obtaining of assistance in evaluating existing record evidence.
The introduction of such evidence into the record upon which the appellate decisions would be based without an opportunity for the parties to comment thereon appears to conflict with certain procedural [277]*277requirements by which the Commission is bound in adjudicating appeals. During the pertinent period, the Commission’s own rules governing the appellate review of adverse personnel actions, for instance, did provide, with one exception not applicable here, that
[a] representative of the Commission shall discuss all relevant representations and evidence with both parties and make the representations and evidence available to them for review.26
5 C.F.R. § 772.304(c) (1974) (emphasis added), presently amended and codified at id. § 772.305(b) (1977). See also id. § 772.308 (1977) (a new provision, not applicable herein, concerning the closing of the record). Furthermore, section 7701 of title 5 27 provides that the Commission shall make its decision “after investigation and consideration of the evidence submitted . . . .” 5 U.S.C. § 7701 (1970) (emphasis added). Though not entirely clear, we believe that this statutory language contemplates that the Commission’s decision will be based on its review of an administrative record which all parties have had an opportunity to review and comment upon. This certainly appears consistent with the Commission’s professed practice, for the Chief of the AEO specifically stated that if appellant did not desire a hearing, which she did not, see Record 26, “his [sic] case will be adjudicated on the basis of the documents of record.” Record 120. See also id. 32.
It is thus our considered opinion that, even though Dr. Eck’s opinion was merely an additional medical evaluation of record evidence upon which appellant had already had a full and fair opportunity to comment, it was also considerably more— being evidence of the type that went to the essence of the validity of the agency’s decision in this case — and therefore appellant should have been afforded an opportunity to review and comment upon it as provided for by Commission regulation.28 While such a practice will inevitably introduce some delay in deciding an appeal, that cost will, at the least, be more than counterbalanced by the benefits derived from the appearance of a fairer adjudication of the merits. Furthermore, the better practice will be to remand the case to the hearing authority to reopen the proceedings in those cases where the Commission is uncertain about the sufficiency of the evidence one way or the other.
Although reception and consideration of this undisclosed additional medical opinion by the AEO constituted procedural error, we hold that such error was not prejudicial and does not warrant reversal of the summary judgment, since in effect the evidence thusly generated was merely cumulative. See Dozier v. United States, 473 F.2d 866, 868 (5th Cir. 1973); Administrative Procedure Act § 10(e), 5 U.S.C. § 706 (1970) (rule of prejudicial error).29 See also Nelms v. United States, 167 Ct.Cl. [278]*278423 (1964), cert. denied, 381 U.S. 943, 85 S.Ct. 1781, 14 L.Ed.2d 706 (1965). Appellant’s claim of prejudice is founded primarily on her assertion that Dr. Eck’s “ex parte” medical opinion supplied the essential, and hitherto lacking, nexus statement establishing the causal relationship between the diagnosed mental disability and the deficiencies identified as justificatory grounds for removal. We view the matter differently.
The AEO expressly stated in its decision that it found the agency had established the required nexus “through the two letters” (fitness-for-duty examination and proposed adverse action letters). It then explained:
Nonetheless, in order to obtain further evaluation of the medical evidence on which the agency had relied in proposing [appellant’s] removal ... we submitted the entire case file to the Medical Division . Bureau of Retirement, Insurance and Occupational Health (BRIOH), U. S. Civil Service Commission for review . . . .”
Record 21. It is quite clear from the first statement, the substance of which we have in effect found to be reasonable, that the AEO would have concluded that the necessary link had been established independent of this supplemental evidence. Where an alleged error in all likelihood would not have affected the result, its occurrence can not have been prejudicial. See Chrysler Corp. v. FTC, No. 76-1586, 182 U.S.App. D.C. 359 at 364-365, 561 F.2d 357, at 362-363 (1977). See also Smith v. Dulles, 99 U.S.App.D.C. 6, 9, 236 F.2d 739, 742, cert. denied, 352 U.S. 955, 77 S.Ct. 329,1 L.Ed.2d 244 (1956). We are also convinced that the impartiality of the AEO, and, more importantly, of the ARB which subsequently took administrative notice- of the additional medical opinion, was not impaired and that, expressly proceeding out of an abundance of caution rather than indecision, the fundamental fairness of appellant’s appeal to the Commission was not vitiated by the AEO’s action. Cf. United States v. Lovas-co, 431 U.S. 783, 790, 97 S.Ct. 2044, 2049, 52 L.Ed.2d 752 (1977) (“due process . must consider the reasons for the [alleged error] as well as the prejudice to the [party alleging it]”).
Despite our holding that a reversal is not compelled on this ground, we add a few words of caution. An employee must be afforded as full and fair an opportunity to make an informed and effective defense as the applicable law permits, not only before the agency, but also before the Commission on appeal. If the right of appeal to the Commission and the procedural safeguards created to assure its impartiality and accuracy of decision are to be something more than a costly facade — a Potemkin village — thrown up to conceal a foregone conclusion, the aggrieved party especially must be afforded a chance to review and comment upon the evidence that is to be considered by those responsible for deciding the appeal. We, of course, do not intend to hamper the Commission with the fear that the validity of its decisions will be jeopardized whenever it attempts better to inform its deliberative process and to assure a correct result. When, however, for whatever reason, it seeks to obtain further evidence against which to adjudge the validity of the agency’s adverse personnel decision, both the Commission’s own regulations and fairness to the individual employee require that such evidence be placed in the record for all the parties to see, and, should they choose, make their views known.
C
We find appellant’s final contention more compelling than her others. In this, she [279]*279argues that, even assuming she labored under a mental handicap, the Government failed to comply with its own regulations by not making “every reasonable effort” to reassign her before seeking her removal for such disability. This failure, she asserts, rendered the Bureau’s personnel action void as procedurally defective.
The source of this particular claim is to be found in certain provisions of the Federal Personnel Manual — the Civil Service Commission’s official vehicle for issuing its personnel regulations, guidelines, and policies to other federal agencies — which seek to guide employing agencies in striking a reasonable balance between the legislative and executive branch policies of utilizing the medically handicapped,30 on the one hand, and, on the other, the practical necessity of assuring the safe and efficient achievement of the agency’s assigned mission. To this end, the Manual provides as follows:
When an employee no longer can perform the duties of his or her position efficiently and safely because of his physical or mental condition, the agency may separate him on the basis of disability. . . . In view, however, of the policy of the executive branch on utilization of employees who are handicapped or who develop handicaps (see subchapters 4 and 8 of chapter 306) every reasonable effort should be made to reassign the employee to duties he can perform efficiently and safely . . . . Specifically, the following alternatives should be considered:
(1) A liberal grant of leave without pay when paid leave is exhausted and the disability is of a remediable nature and likely to respond to treatment and hospitalization. Many mental and emotional disorders, formerly considered completely disabling, now fall in this category in view of the dramatic medical advance made in treatment and rehabilitation of these conditions in recent years.
339 FPM 1-3(b)(1) (Mar. 1972) (emphasis added).
From our review of the administrative record, we are left with the distinct impression that in fact no real effort was ever made to reassign appellant to other duties in which she might have performed more satisfactorily. For instance, the Chief of ORTS, where appellant worked, testified that he arranged to have her detailed on a temporary basis to the Bureau’s Technical Services Division “where there was need of a clerk-typist for a period of one week.” Tr. 185. When asked why appellant had been returned after only one week, this witness offered the following testimony which underscores the rather feckless efforts to reassign appellant:
Q. Why did you have her transferred?
A. Well, I thought she would be less potential complex [sic] and so on. If it was true there was any possible friction between herself and [a co-worker].
Q. Did you feel that this might be a possibility, that some of these things were personality differences between [the co-worker]?
A. I thought this might be a possibility, but it was the only move that I could make to try to alleviate the situation and it wasn’t a successful one. I think the following week, ORI, located someone for this particular vacancy. However, it was done at my specific request. As I recall, the people in Technical Services Division weren’t particularly happy about the situation. I had her detailed there, I had it done. They would rather have had someone else or didn't feel her work was entirely satisfactory, but there was no incidence involved there from the mental condition or anything like that. I didn’t hear any comments of that sort from . the Superintendent of the Division at the time .
Q. Did he give you any reason; what was the reason why she came back if, you know what the reason was?
* * * * * *
A. I think the precipitating reason was a person had been located to fill the job. Otherwise, I would perhaps have insisted [280]*280that they try keeping her a bit longer, to see if that would work, because there was a lot of unhappiness or potential friction to develop because the situation had gone on for some months.
Tr. 199-201.
The head of another Bureau office for whom appellant had done considerable work also testified that he had informally suggested that she be reassigned to him in light of the apparent problems in her present job. Tr. 249. He considered their general relations to be excellent and her work to be most satisfactory at times, though not so at other times. Id. 251-53. Notwithstanding the need for another clerk-typist in this office, appellant was not reassigned there ostensibly because the Assistant Chief of ORTS believed that there simply was not enough room to accommodate the necessary equipment. Id. 236. .When asked whether he ever approached anyone about the possibility of a transfer, this latter official further testified that he had brought the matter up with the ORTS Chief who merely responded “[tjhat he didn’t see where it would do any good, because nobody else would be willing to accept her.” Id. 233. Without belaboring the point further, we believe it rather obvious from the foregoing that, while some consideration was given, the agency made no real effort to reassign appellant to other duties.
Without specifying exactly what they were, the Government asserts to the contrary that in fact “[ejfforts were made to locate other, suitable positions, and she was given a temporary detail.” Government’s Brief at 12. In fact, it never presses the point with any zest, preferring instead to shift emphasis from the extent of efforts expended to the feasibility of reassignment. In this regard, the Government refers us to the AEO’s conclusion which, it correctly maintains, we should not ignore by merely substituting our own judgment.
[T]he appellant was placed on one detail and some effort was made to locate other positions for her. It was within the agency’s prerogative to make the decision that after receiving the report from her fitness-for-duty examination which stated that she was not fit for duty, that reassignment was not a feasible alternative. Medical advice and opinion were obtained throughout the proceedings leading to appellant’s removal. We find no impropriety in the agency’s accepting the medically based decision that removal rather than reassignment was the appropriate and best course of action for all concerned.
Record 20 (emphasis added); Government’s Brief at 12 — 13. This reasoning, however, plays fast and loose with the facts, for in actuality, apart from Dr. Valle’s terse, hand-scrawled “not fit for duty at this time”, there was no medically-based decision whatsoever that “removal rather than reassignment was the appropriate course of action for all concerned . . .,” or that “[a] liberal grant of leave without pay” would have been futile.
Whether what appears to have been inadequate affirmative reassignment effort or consideration of the liberal leave-without-pay option entitles appellant to the relief she seeks is quite a different matter, however. It is, of course, well-established that an agency must abide by its own regulations in effecting the removal of one of its employees. See Vitarelli v. Seaton, 359 U.S. 535, 79 S.Ct. 968, 3 L.Ed.2d 1012 (1959); Service v. Dulles, 354 U.S. 363, 77 S.Ct. 1152, 1 L.Ed.2d 1403 (1957); Mazaleski v. Treusdell, No. 75-1817, 183 U.S.App.D.C. 182, 562 F.2d 701 (1977). If the Manual provision to which appellant now refers us is indeed a binding regulation and if the agency has failed to comply with its mandate to the prejudice of its employee, then an essential predicate to a valid removal will have been wanting. We must thus address the question whether the above-quoted provision in the Manual is a regulation or something less which does not give employees enforceable substantive rights.
We begin our analysis with the rather obvious proposition that not “every piece of paper emanating from a Department or Independent Agency is a regula[281]*281tion.” Piccone v. United States, 407 F.2d 866, 877, 186 Ct.Cl. 752 (1969) (Nichols, J., concurring); see McGlasson v. United States, 397 F.2d 303, 308-09, 184 Ct.Cl. 542 (1968); Greenway v. United States, 175 Ct.Cl. 350, 362 n.5, cert. denied, 385 U.S. 881, 87 S.Ct. 167, 17 L.Ed.2d 108 (1966). It is less clear, however, to what extent provisions of the Manual not also published in the Federal Register or Code of Federal Regulations are mandatory rather than merely precatory. See Piccone, supra, 407 F.2d at 871-72 n.12. Certainly much of the Manual is not mandatory,31 but some unpublished provisions may be binding if so intended by the Commission. Thus, to determine the effect of a Manual provision, a court must determine the Commission’s intent in authoring it, as ascertained by an examination of the provision’s language, its context, and any available extrinsic evidence. This inquiry is not well suited to an appellate court, however, and consequently we must remand the case to the district court for resolution of this point. We of course recognize that the provision in question employs the directory “should be” rather than the mandatory “shall” or “must”, but this should not be automatically determinative of the issue. Cf. Thompson v. Clifford, 132 U.S.App.D.C. 351, 355, 356, 408 F.2d 154, 158-59 (1968). Particularly in this instance, this superficial indicium of intent should be weighed against the rather strong expressions of congressional, executive, and Commission policy favoring a liberal employment of the mentally and physically handicapped32 and any evidence that the [282]*282Commission or the agency have by their past actions created a “common law” of reassignment or of granting leave-without-pay. We also note that so far neither the Bureau, AEO, ARB, previously, nor the Commission in this litigation, has claimed that the subject provision is not a binding regulation.
If on remand it should be found that the Manual provision, 389 FPM 1 — 3(b), is mandatory rather than precatory, a further remand to the Commission will be necessary in order to adduce sufficiently complete and detailed medical evidence to permit both it and the reviewing courts to determine whether the agency abused its discretion in not reassigning appellant or placing her on extended leave-without-pay in light of the nature and chronicity of the disability as well as the availability of other suitable positions.33 Although the Manual’s numerous regulations, instructions, and suggestions relating to adverse actions based on medical disabilities, taken together, are something considerably less than a paradigm of clarity, we are of the conviction that to remain consistent with the evident spirit of Commission policies towards the physically and mentally handicapped, an employing agency must exercise an informed discretion in determining whether reassignment or leave-without-pay are feasible alternatives to removal. An informed exercise of discretion, we think, necessarily contemplates a comprehensive and detailed report of psychiatric examination so as adequately to inform the agency as to the scope of the medical problem. We note that the Manual specifically requires:
If it is determined that removal (rather than reassignment or retirement) is in order, the agency should obtain a complete and detailed report of physical examination without cost to the employee. [283]*283The employee should be referred for medical examination with a statement of the particular demands of the position and a statement of how the employee’s performance or behavior fails to meet these demands. . . . This medical report is furnished to the Commission, upon its request, for appellate review of the removal or for other purposes.
752-1 FPM S1-3(a)(5)(b) (Feb. 1972). This so-called fitness-for-duty examination, as we have seen, is required whenever an agency “has a question about the physical or mental capacity of an employee” and seeks to justify an adverse personnel action upon such capacity. Id. S1-3(a)(5)(c). However, it is not administered solely as a necessary predicate to removal, for as the Manual itself emphasizes: “[a] fitness-for-duty medical examination will be valuable in counseling the employee and determining the feasibility of alternative actions available to the agency.” 339 FPM 1 — 3(c) (Mar. 1972).
Although we have determined that the fitness-for-duty examination report sufficed to establish a rational basis for the Bureau’s adverse action, at least when viewed in relation to the other medically-related evidence, we do not consider the simple statement, “Schizophrenia, chronic-undifferentiated, compensated. ‘Not fit for duty at this time’,” to be an adequate basis for an agency to assess either the feasibility of immediate reassignment or the likely value of placing the employee on leave-without-pay status. This “diagnostic impression” is little more than an ultimate conclusion unsupported by reasons or any detailed explanation that might give some substance to it.34 Such intractable psychiatric terminology can be of little assistance to the employing agency in evaluating the actual extent of and prognosis for an employee’s psychiatric disability. As in the context of the insanity defense in a criminal trial,35 the role of the psychiatrist in our legal system must not be perverted so that the government’s actions against an individual degenerate into a “trial by label”. In order for it adequately to assess the feasibility of pursuing alternative measures, such as reassignment to a less-demanding position or a liberal allowance of leave-without-pay, the agency must be informed with reasonable particularity concerning its employee’s medical disability. Agency officials entrusted with personnel administration are not, on the average, in any better position to comprehend the signification of psychiatric labels — e. g., schizophrenia, paranoia, neurosis, etc. — than jurymen entrusted with passing upon an insanity defense, when little else is offered by way of explanation. The terms should at least be defined, and the significance of the diagnosis and prognosis explained in reasonable detail and in a manner that relates both to the employee’s current and project[284]*284ed capacity to perform his or her work satisfactorily. Cf. Washington v. United States, 129 U.S.App.D.C. 29, 39, 390 F.2d 444, 454 (1967) (insanity defense context).
Our holding here is not a quixotic one, for both Dr. Bernet’s prognosis, see Record 84-88, and Dr. Valle’s testimony at the hearing, Tr. 52, as well as appellant’s behavior after the fitness-for-duty examination, are good indications that, at the least, a liberal extension of leave-without-pay, coupled with continued medical treatment, may indeed have been both feasible and fruitful.
IV
For the reasons set forth above, the judgment of the district court appealed herein is vacated and the case remanded to it for determination whether Federal Personnel Manual Provision 339 FPM 1 — 3(b)(1) (Mar. 1972) was binding on the Bureau, and if so, for further remand to the Commission to obtain a more complete psychiatric report by which the present feasibility of alternative actions may better be judged.
So ordered.