The hyphen is a problem with the Search feature.
If I search the following keywords:
+hide +e-mail
the search engine interprets it as
+hide +e -mail (20976 results)
as if I had told it to exclude 'mail' from the search.
You can verify this by searching
+hide -mail +e
and you get the same results set. (20976 results)
Since the search feature ignores the 'e', the original search
+hide +e-mail
effectively becomes
+hide -mail (20976 results)
The user has to know to use quotation marks to prevent this
+hide +"e-mail"
which is not in the instructions.