;; an example, if the value is `buffer-file-name' then all buffers
;; who are visiting files are suitable, but others (like dired
;; buffers) are not;
-;; * a list -- then the buffer is suitable iff its mode is in the
+;; * a list -- then the buffer is suitable if its mode is in the
;; list, except if the first element is `not', in which case the test
;; is reversed (i.e. it is a list of unsuitable modes).
;; * Otherwise, the buffer is suitable if its name does not begin with