term:

Specification

specification n

: a detailed precise presentation of something or of a plan or proposal for something: as
a : a written statement containing a description of particulars (as of charges or contract terms)
b : a written description of an invention or discovery for which a patent is sought that embodies the manner and process of making and using the invention or discovery and concludes with a claim of that aspect for which the applicant demands credit
c : a written description of construction work to be done forming part of the contract usually used in pl.