+`folder:` search will match the folder of any of the files. The
+`--output=files` option outputs all the files of all matching messages.
+
+## Shouldn't notmuch support inline PGP?
+
+[Why it might not be a good idea](https://dkg.fifthhorseman.net/notes/inline-pgp-harmful/)
+
+## How do I delete messages
+
+See [[excluding]].
+
+## How do I configure the citation line when replying in Emacs?
+
+ (setq message-citation-line-format "On %a, %d %b %Y, %f wrote:")
+ (setq message-citation-line-function 'message-insert-formatted-citation-line)
+
+See help for `message-citation-line-format` for details.
+
+## How do I search for messages that have no tags?
+
+Unfortunately, there is no way to do this directly.
+
+However, it's possible to accomplish this using two searches in shell. First,
+you need to query all tags in the database, and transform the result into a
+query that matches messages that have none of those tags:
+
+ $ notmuch search --output=tags \* | sed 's/^/not tag:/;2~1s/^/and /'
+
+Next, use that to query the messages:
+
+ $ notmuch search $(notmuch search --output=tags \* | \
+ sed 's/^/not tag:/;2~1s/^/and /')
+
+## How do I search for punctuation, specific special characters, or regexp?
+
+Please see the [[notmuch-search-terms manual
+page|manpages/notmuch-search-terms-7]] first,
+
+The main thing to understand is that Xapian, and therefore Notmuch, searches are
+closer to natural language searches than regular expression
+searches. Punctuation is mostly ignored.
+
+The boolean prefix searches (see Boolean and Probabilistic Prefixes in the man
+page), such as tag: or path: searches, need an exact match.