Please add support for Lisp tags/symbols (or support Exuberant CTags which does it).
Also, the Code Folding could recognize top-level block comment sections, i.e. multi-line between #| |# and also contiguous runs with the same number of semi-colon prefixes. For example:
;; a three line comment
;; line two
;; third line
The #| |# are most important, since the ;; kind are typically shorter.
Thanks for your great work on Geany!
(ref: v 0.21 on Linux, OS X, and Windows7)