Final answer:
The requirement to research prior listings of the subject property within the last 12 months is a Fannie Mae/Freddie Mac requirement, necessary for a comprehensive appraisal.
Step-by-step explanation:
The requirement to research prior listings of the subject property within the last 12 months is a Fannie Mae/Freddie Mac requirement. The appraisal must include an analysis of any prior listings of the subject property in the last year, according to the selling guides of Fannie Mae and Freddie Mac. This analysis provides insight into the property's market history and helps in assessing its market value. This is a standard procedure that's employed in the appraisal process to ensure that the appraiser has taken into consideration the complete history of the property which could affect its current market value.