what does <C-\>^] mean in vim mapping?

Question

Says in the gtags tutorials: Suggested map:

    map <C-\>^] :GtagsCursor<CR>

Though the mapping of :GtagsCursor to ^] seems suitable, it will bring an
inconvenience in the help screen. 

I guess ^] should mean CTRL-], but cannot find explicit descriptions about it in the chapter "key-mapping". Another question is if ^] is CTRL-], why use ^] here?

Answer 1

This is indeed inconsistent, and would be more understandable as :map <C-\\><C-]> . In Vim (as well as in terminals), the combination of [ + Key stands for the single <C-Key> . You'd enter this via <CV><C-]> , not as the two characters ^ and ] .

The mapping suggests the combination of Ctrl with two keys because <C-]> by itself is already taken for keyword jumps.