Characters Used in Expressions

The following list documents the special meaning attached to
characters used expressions, other than the special case "regular
expressions". For the special characters used in regular expressions,
see Regular Expressions Reference.

& The "and" symbol is equivalent to the operator and.
| The vertical pipe symbol is equivalent to the operator or.
! The exclamation mark is equivalent to the operator not.

= The equal sign indicates an exact match, when preceding a word
sequence.

[...] Square brackets in expressions can be used to represent a
quantifiable range (e.g., [*,100] means 100 lines or less).
, The comma is used within the square brackets (see above) to
establish a line range.
( ) Parentheses are used to establish precedence of operators in
compound expressions.
: The colon is treated as a subject or author qualifier (i.e., subject:, author:).

* The star character is treated as a wildcard. When attached to
words, it matches any additional characters attached to the word.
Alone, the wildcard matches anything. (See Wildcard below for more
details.)

Forcing an exact match using the equal sign
To force an exact match of a word or word sequence, you will precede
the word or sequence of words with the = character. This will match
messages that contain the exact word or sequence of words, including
instances where the word sequence is followed by punctuation. Here
are a few examples:
Example 1 - subject: =apple
would match apple or APPLE!!!.
But it would not match red apple or apple pie or Orange.
Example 2 - If you want to force Agent to do an exact match, but also
to include re: in the match (for responses), you can do something like
the following:
subject: re and =apple
This filter will only match subjects which contain (exactly) apple and
which also contain re.

Example 3 - For an exact match of the address: "jdoe@acmeinc.com(John
Doe)", you need to use author:= "jdoe@acmeinc.com (John Doe)" instead
of author:= John Doe.

Identical phrases with different punctuation and spacing
Other than the characters with special meaning listed above, Agent
ignores all other punctuation and spacing in expressions. Thus, the
following phrases are all identical:

Mark F. Sidell <mark.sidell@forteinc.com>
Mark F Sidell mark sidell forteinc com

Mark-F-Sidell-mark-sidell-forteinc-com

Here's another example. To match the following URL
http://www.forteinc.com/
you can use any of the expressions below:

http":"//www.forteinc.com/
http www forteinc com

http-www-forteinc-com

Qualifiers range

The expression subject: agent and forteinc searches for agent in the
subject only, but searches for forteinc in both the subject and
author. You can define a field-qualified Boolean expression by
enclosing it in parentheses (...).

For example, for the expression "subject: (agent and forteinc)", Agent
searches for agent and forteinc in the subject only.

Line range
The range [10,20] matches all messages with at least 10 lines and no
more than 20 lines.

A * in place of one of the numbers is a wildcard. For example, [*,10]
matches all messages with no more than 10 lines, and [15,*] matches
all messages with at least 15 lines.

Pasted punctuation and symbols
When you use the Paste button on the Add Usenet Filters and Add Email
Filters dialog box to paste subject or author of a message, the
following punctuation and symbols are converted to a space:
& | ! = [ ] , ( ) { } * " : <tab> <space>

If there are more than one of these characters in a row, they'll all
be converted to a single space.

See Also:
How to Create Message Filters
Agent's Expression Language
Regular Expressions Reference
Expression Examples
How to Filter Out Spam
How to Create View Filters