When using Emacs 23.1.1 and trying to install the speedbar package on
a Debian system, I got the following warning message:
install/speedbar: Handling install for emacsen flavor emacs23
Loading `dframe': old-style backquotes detected!
In toplevel form:
dframe.el:121:1:Warning: !! The file uses old-style backquotes !!
This functionality has been obsolete for more than 10 years already
and will be removed soon. See (elisp)Backquote in the manual.