Short form: you can post a link to a known, existing online business such as a FLGS, or name of an established business such as Ral Partha Europe, that you're not associated with, to help out another player. Eg. "You can buy minis from Ral Partha Europe or BV Traders".
What we won't accept is people advertising their business, or blatantly attempting to drum up business with which they are associated with, unless they ask permission of the site Admins first. The site Admins (same as forum admins) are myself (Worktroll), and Chunga. The reason for this should be clear - we cannot accept any responsibility for commercial transactions made on the basis of information on this site, so we need to be able to approve or disapprove any posts soliciting such commerce.
Does that help?
And folks, remember - if you're not sure if something you'd like to post nudges up against a rule, you can always PM a moderator for advice.
Worktroll, Administrator.