I think that "go check out my fic for this challenge" would be pushing it on AO3, because that's less of a community promotion and more of an invitation to read your work elsewhere. Promoting the comm itself is fine, but anything that implies "go read (and vote for) my specific fic here" would be against the spirit of the rule, if not the letter. Basically, if you can phrase it as promoting the community, that's fine, but if it's more about promoting your fic by way of linking to the community, that's a no. Does that help clear it up?
no subject
I think that "go check out my fic for this challenge" would be pushing it on AO3, because that's less of a community promotion and more of an invitation to read your work elsewhere. Promoting the comm itself is fine, but anything that implies "go read (and vote for) my specific fic here" would be against the spirit of the rule, if not the letter. Basically, if you can phrase it as promoting the community, that's fine, but if it's more about promoting your fic by way of linking to the community, that's a no. Does that help clear it up?