What does "[h:a]" in the status bar mean?

[jingchengx]

I went through the documentation and didn't find what it was for...

[ahrm]

It means the current highlight type is 'a'. For example used with add_highlight_with_current_type command among other things.

[ascyii]

I would wish to see a feature to disable this info in the statusbar :)

[ahrm]

In the development branch you can customize the statusbar completely using the status_bar_format config variable.