Sure you could do a specific CSS class but unless you get all the potential users to add the .unsafe { blah blah } snippet to their CSS configuration then it's a moot point. I'm just thinking that if that went into the site documentation somewhere that it'd be mostly invisible since I don't expect people would notice. That's a guess anyway. I think all I'm reall saying is that you absolutely cannot count on color being available as a device for communication. It's quite obvious that if you prepend some sort of warning text like "Potentially Unsafe Link<a href="mocha:alert('foo!')" >link</a> that something is going on.

__SIG__
printf "You are here %08x\n", unpack "L!", unpack "P4", pack
  "L!", B::svref_2object(sub{})->OUTSIDE;
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If you look back, you'll notice my original proposal did include some text.. :-)

Makeshifts last the longest.