I've often thought that we should come up with a well-rounded caveat, and then people could put it in their sigs, or maybe have a link to a page or a message thread that contains its text, etc.
"Of course, there are details, some of which might be important to your particular factual situation, which I certainly don't know, and as to which I haven't asked all the questions that one would need to ask in order to ferret out other potentially relevant issues (meaning my comments here and elsewhere on thesde message boards are intended to be helpful information, but you should not and cannot rely upon them as my legal or other professional advice)."
(First draft)