I just got a spam with this tag:
. . . This message is sent in compliance of the new email Bill HR 1910. Under Bill HR 1910 passed by the 106th US Congress on May 24, 1999, this message cannot be considered SPAM as long as I include a valid return address and the way to be removed. . . .
Traditionally the ‘law’ cited is Section 301 of HR 1618, if memory serves, and I hadn’t seen it given a date before.