This article is from the alt-sources-mac FAQ, by Mark Pilgrim (firstname.lastname@example.org) with numerous contributions by others.
Do not post copyrighted source code that is not yours unless you have
permission from the original author. This includes posts you see on
other newsgroups; always consult the original author before cross-posting.
Do not post something that can only be decompressed with a commercial
decompression program. If you insist on compressing your source archive
with a commercial compression program, make sure that either (a) it can be
decompressed with a free/shareware program, or (b) it is self-extracting.
Do not post source code to viruses or intentionally malicious software.
Do not post anything that doesn't include some sort of Mac source code (see
<1.3>, <2.1> above).