Stefan Monnier schrieb am Mo., 22. Juni 2015 um 03:18 Uhr: > > If this is generally unsupported, can we then remove it from the doc and > > Yes. Do you happen to know where it's documented? > https://www.gnu.org/software/emacs/manual/html_node/elisp/Basic-Char-Syntax.html "You can use the same syntax for punctuation characters, but it is often a good idea to add a ‘\’ so that the Emacs commands for editing Lisp code don’t get confused. For example, ‘?\(’ is the way to write the open-paren character. If the character is ‘\’, you must use a second ‘\’ to quote it: ‘?\\’." Here I would put ( and ) into the same category as \, so that it's not only "a good idea" to escape it. "However, you should add a backslash before any of the characters ‘()\|;'`"#.,’ to avoid confusing the Emacs commands for editing Lisp code." Here I would make escaping mandatory for the first three characters (or even for all of them). > > > have the reader print a warning (or reject it altogether)? > > We can't reject it, because I'm pretty sure there's code out there which > uses it. I'd accept a patch which adds a warning for it, > > > OK, I'll try to come up with a patch.