A buyer broker agreement is a contract with the buyer and the broker to work together for a specified time period to help the buyer find a property.
Posthumous [ a. - Born after the death of the father, or taken from the dead body of the mother; as, a posthumous son or daughter. - Published after the death of the author; as, posthumous works; a posthumous edition. - Being or continuing after one's death; as, a posthumous reputation. Meaning of 'posthumous' (Princeton's WordNet)
A retrospective, generally, is a look back at events that took place, or works that were produced, in the past. As a noun, retrospective has specific meanings in medicine, software development, popular culture and the arts. It is applied as an adjective, synonymous with the term retroactive, to laws, standards, and awards.