Turns out it isn't legally obligated but it is explicitly discouraged by the government in the Federal Acquisition Regulations https://www.acquisition.gov/far/c

Turns out it isn't legally obligated but it is explicitly discouraged by the government in the Federal Acquisition Regulations https://www.acquisition.gov/far/current/html/Subpart%2037_1.html https://www.acquisition.gov/far/current/html/Subpart%2037_1....