1. Property names with -'s are not handled properly Specifically, the escapes are not removed. Ex: (org-make-tags-matcher "PROP\\-WITH\\-HYPHENS=2") produces ("PROP\\-WITH\\-HYPHENS=2" and (progn (setq org-cached-props nil) (= (string-to-number (or (org-cached-entry-get nil "PROP\\-WITH\\-HYPHENS") "")) 2)) t) The property name in the matcher should be "PROP-WITH-HYPHENS". The original code /does/ instead remove -'s from tag names, which shouldn't have them anyway. I suspect that this was intended for property names rather than tag names. 2. Incorrect comparison operators allowed, produce bad matchers. The regular expression "[<=>]\\{1,2\\}" is used to detect the comparison operators. But this can produce bad matchers that fail opaquely at match time rather than giving an appropriate error message at parse time. Ex: (org-make-tags-matcher "P<<2") produces ("P<<2" and (progn (setq org-cached-props nil) (nil (string-to-number (or (org-cached-entry-get nil "P") "")) 2)) t) 3. A faulty test for todo matcher in org-make-tags-matcher The current code uses (string-match "/+" match) to detect the presence of the shortcut /!? style todo matchers. But this is insufficient. Ex: (org-make-tags-matcher "PROP={^\\s-*// .*$}") produces an erroneous matcher: ("PROP={^\\s-*// .*$}" progn (setq org-cached-props nil) (member "PROP" tags-list)) We want to find the first slash that is not enclosed in {}'s or ""'s; if found, a todo match is needed. A simple pattern will not be enough for this. As a side note, org allows arbitrary characters in TODO keywords, (For instance, both PROP={/!} and PROP="/!{/!}" are valid TODO keywords (it works!) *and* valid property comparisons.) The assumption of the current version is that {}'s and "'s are excluded. I also exclude ()'s from TODO keywords in the new version for reasons we can discuss later. Neither seems like a big loss. If you are using {}'s, "'s, or ()'s in your TODO keywords, use a TODO= match rather than a /!? match. 4. Regexp matchers in todo queries fail when no TODO for an item. Ex: (org-make-tags-matcher "/{\\S-}") produces ("/{\\S-}" and t (string-match "\\S-" todo)) This will raise an error when todo is nil (no todo keyword on a scanned item) when doing an org-map-entries, say. The todo should be replaced with a (or todo "") as it is for tag-style TODO queries. 5. A minor consistency issue At line 7179 in org.el (v 7.8.11), missing an org-re call in a regex that uses posix classes. The org-re is used elsewhere, for xemacs compatibility, I think. [FWIW, all of these are problems eliminated or made moot in the new parser.]