Query
Single term query
This query specifies only one term for retrieving all of the documents which contain that term, for example:

namazu

AND query
This query specifies two or more terms for retrieving all of the documents which contain both terms. Insert the and operator between the terms, e.g.

Linux and Netscape

You can omit the and operator. Terms which are separated by one ore more spaces are assumed to be an AND query.

OR query
This query specifies two or more terms for retrieving all documents which contain any one term. Insert the or operator between the terms, e.g.

Linux or FreeBSD

NOT query
This query specifies two or more terms for retrieving all of the documents which contain a first term but do not contain the following terms. Insert the not operator between the terms, for example:

Linux not UNIX

Grouping
You can group queries by surrounding them by parentheses. The parentheses should be separated by one or more spaces. e.g.

( Linux or FreeBSD ) and Netscape not Windows

Phrase searching
You can search for a phrase that consists of two or more terms by surrounding them with double quotation marks or braces such as "..." and {...}. In Namazu, the precision of phrase searching is not 100 %, so wrong results may occasionally occur. Example:

{GNU Emacs}

Substring matching
The are three types of searching by substring matching.

Prefix matching
inter* (terms which begin with inter)
Inside matching
*text* (terms which contain text)
Suffix matching
*net (terms which terminated with net)
Regular expressions
You can use regular expressions for pattern matching. The regular expressions must be surrounded by slashes like /.../. Namazu uses Ruby's regular regular expressions engine. It generally offers a Perl compatible flavor. e.g.,

/pro(gram|blem)s?/

Field-specified searching
You can limit your search to specific fields such as Subject:, From:, Message-Id:. This feature is especially convenient for Mail/News documents, for example:

+subject:Linux
(Retrieves all documents which contain Linux in a Subject: field)
+subject:"GNU Emacs"
(Retrieves all documents which contain GNU Emacs in a Subject: field)
+from:foo@example.jp
(Retrieves all documents which contain foo@example.jp in a From: field)
+message-id:<199801240555.OAA18737@foo.example.jp>
(Retrieves a certain document which contains specified Message-Id:)

Notes
In any queries, Namazu ignores case distinctions of alphabet characters; i.e. Namazu does case-insensitive pattern matching.
Japanese phrases are automatically segmented into morphemes and are handled as phrase searching. This process occasionally causes invalid segmentation.
Letters, numbers or parts of symbols (duplicated in ASCII) which are defined in JIS X 0208 (Japanese Industrial Standards) are handled as ASCII characters.
Namazu can handle a term which contains symbols like TCP/IP. Since this method of handling isn't complete, you can also describe the term as TCP and IP instead of TCP/IP, but it may cause noisy results.
Substring matching and field-specified searching takes more time than other methods.
If you want to use and, or or not simply as terms, you can surround them with double quotes or braces like "..." or {...}.