The Specifications (CDC) is a contractual document to be respected during a project. The specifications allow the project owner to let the project manager know what he expects of him when carrying out the project, leading to penalties in the event of non-compliance.
In regards to:
For all the information on CDCs in architecture, you can find a practical guide from the site Architecture markets.
Find the models of specifications here !
For information relating to specifications in general, find all the information on the site: https://cahiersdescharges.com/comment-faire-cahier-des-charges/