Anthem of the USSR

So, this is really more of a cultural question than anything else....

Here in the US, we play/sing The Star-Spangled Banner on a variety of occasions, including sports events (baseball games). I'm interested in learning more about the Anthem of the USSR in that context, especially from 1977 on, when the lyrics were "adjusted."

Specifically, what is the etiquette when singing the Anthem? On what occasions would you expect to hear it, or sing it?

I'm including the links to two recordings I've found--they are downloads, not direct links--for the 1944 and 1977 versions. Beautiful music, too--the 1944 version, sung with so much passion and conviction, is enough to make me catch my breath.

http://www.sovmusic.ru/english/download.php?fname=ussr44

http://www.sovmusic.ru/english/download.php?fname=ussr2

Also, I can recommend the above website as a fantastic resource for anybody wanting older Soviet music.