But your regex contains .* and this results in just the four letter word RTFM, which I hate with a passion in its standalone version.

Shouldn't we all remember that RTFM is a protocol prefix and requires an obligatorie MEME URI which provides at least an additional hint or keyword?

So the proper use should be a still sufficiently terse RTFM://<check_both_quoting_and_consider_rethinking_your_approach>.