Matching Text Patterns
Like locators, patterns are a type of parameter frequently required by Selenese commands. Examples of commands which require patterns are verifyTextPresent, verifyTitle, verifyAlert, assertConfirmation, verifyText, and verifyPrompt. And as has been mentioned above, link locators can utilize a pattern. Patterns allow you to describe, via the use of special characters, what text is expected rather than having to specify that text exactly.
There are three types of patterns: globbing, regular expressions, and exact.