reference-style/shortcut syntax

[Richard Taytor]

I also agree that single bracket reference-style syntax is not prudent. As Jacob suggested, it creates ambiguity for the reader (Is it an edit or a link?). It also creates a new problem of potential conflict, however rare that may be.

It seems reasonable to prefix a marker colon (possibly followed by whitespace):

[:ref link] or [: ref link]

And perhaps the same for attributes:

{:att ref} or {: att ref}

This syntax is also more coherent with the footnote syntax[^1] (which also prefixes a marker). It simply seems prudent to me. Comments?