add note about message-templ

[notmuch-wiki] / faq.mdwn

diff --git a/faq.mdwn b/faq.mdwn
index d6112132148a0c9682c702b73c2ff4c3c9669a7b..bb0efaa90c2b458ca5e6ec9ea1486e52d7da072a 100644 (file)
--- a/faq.mdwn
+++ b/faq.mdwn
@@ -26,3 +26,30 @@ See [[excluding]].
         (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.