Wildcard expressions When completing configuration activities on an appliance, you can use wildcard expressions for several purposes, for example, to match URLs on blocking lists and whitelists. There are two types of wildcard expressions you can use: Glob expressions — Using these is the default. More information about this type of expressions is, for example, provided on the following Linux man page: glob(7) Regular expressions (Regex) — If you want to use these, you need to type the term regex first and then include the regular expression in parentheses, for example: regex(a*b) The regular expressions that are used on the McAfee Web Gateway appliance follow the Perl Regular Expression syntax. Information on this syntax is, for example, provided on the following Linux man page: perlre(1) List of special glob characters The following table provides a list of important special characters you can use to create glob-type wildcard expressions. List of special regex characters The following table provides a list of important special characters you can use to create regex-type wildcard expressions.