What if "http:" was a namespace like
"user:", you would use
[[namespace:<data>]] for all sorts of links and that would be it.
No more bare URLs and no [URL] with single brackets.
Hmm. That might work too, and would be even simpler. Thanks for
the suggestion--I solicit comments on that as well. I don't think
it would be too bad, though, to have an "external/internal"
separation between one-bracket and two-bracket links if your idea
has some technical problem I don't see right now. That's pretty
simple to understand an use.