§ 34.1-2-311 — Options and cooperation respecting performance

(a) An agreement for sale which is otherwise sufficiently
definite (section 34.1-2-204(c)) to be a contract is not made
invalid by the fact that it leaves particulars of performance to
be specified by one (1) of the parties. Any such specification
must be made in good faith and within limits set by commercial
reasonableness.
(b) Unless otherwise agreed specifications relating to
assortment of the goods are at the buyer's option and except as
otherwise provided in section 34.1-2-319(a)(iii) and (c)
specifications or arrangements relating to shipment are at the
seller's option.
(c) Where such specification would materially affect the
other party's performance but is not seasonably made or where
one party's cooperation is necessary to the agreed performance
of the other but is not seasonably forthcoming, the other party
in addition to all other remedies:
(i) Is excused for any resulting delay in his own
performance; and
(ii) May also either proceed to perform in any
reasonable manner or after the time for a material part of his
own performance treat the failure to specify or to cooperate as
a breach by failure to deliver or accept the goods.