Add-Edit: Rule fields
Generally speaking, it is best to create spam-filtering rules by defining only one or two criteria in the Add/Edit Rule page.
For example, if you are defining spam-filtering rules that are based on actual spam mail, define the rule using only the mail's Subject: field, or only the Sender: field. The more criteria you specify for any given rule, the less chance of stopping similar, but not identical, violations.
The criteria you specify are evaluated exactly as they are entered, including any quotes, spaces and punctuation. Phrases are treated as a single unit. Only when each word, space, comma, etc. in the phrase appears in the message in the order entered, will a match be triggered.
Do not use quotes to signify a phrase, or commas to separate multiple words entered in a single field. Instead, create separate rules.
See also:
Add-Edit: Rule Name
Current Rules
Creating A Keyword List: Example