Elisp manual, node Defining Minor Modes, doc for C-c

[Drew Adams]

This is what the Elisp manual, node Defining Minor Modes, says about key
bindings:

 The key sequences bound in a minor mode should consist of `C-c'
 followed by a punctuation character _other than_ `{', `}', `<', `>',
 `:', and `;'.  (Those few punctuation characters are reserved for major
 modes.)

It's not clear what is meant here by a punctuation character. Is it a
character with a punctuation syntax class, or is the set of possible
characters here fixed?

If it's the former, then we should say so, for clarity, and mention the
buffer (minibuffer?) whose syntax table is used.

If it's the latter, then it would be better to simply list the punctuation
characters that are allowed - otherwise, how will a user look up that list?