Re: vc-set-mode-line-busy-indicator

[Richard Stallman]

    > They do not seem similar to me.  `highlight' is used for highlighting
    > text that is always present, and could be used on any text.

    `mode-line-highlight' is currently used for the same purposes on the
    mode line - for highlighting text that is always present on the mode line.

After checking the code, I think you are right.  Someone else compared
`mode-line-highlight' to buttons, so I based what I said on that, but
now I think that isn't really so.  This text is only partly like a button.