[magicalist]

The form is linked to multiple times in the same FAQ. If you want the DMCA requirements, you can find them here:

http://www.law.cornell.edu/uscode/text/17/512#c_3

edit: I'm not exactly sure what you're asking with "legally enforceable", but again, if you mean in terms of the DMCA, my understanding is that if a notification satisfies those requirements, you must comply. That's why the counter-notification process is so important.

[girlvinyl]

Small correction: You must comply if you intend to keep yourself protected by the safe-harbor provisions specified in the DMCA. If you do not comply, you then become exposed to liability, though not necessarily guilty of infringement.