Rules to match domains containing exact numbers of components

Special patterns of the form ,  ,  , etc.,  may be used to provide penultimate, fall-through matches for domains containing the specified number of components (the same number of components in the original host/domain specification as the number of asterisks in the pattern). A rewrite rule pattern with the same number of asterisks as components in the original host/domain specification will be checked after the comparison of the original, unmatched host/domain specification against the channel host name table, and before the "." match-all rule. That is, when no more specific rewrite rule match has been found, nor has a match been found in the channel host name table, then all components of the original host/domain specification are replaced by asterisks for one last probe (prior to the "." match-all rule). If a rewrite rule pattern containing that exact same number of asterisk components is found, then that rewrite rule is considered to match the host/domain and is applied.

One of the more common uses of this form of pattern is that of a   pattern for matching all short form host names (host names unadorned by any higher-level domain components). For example: &#x2a;      $U%$H.domain.com (Though in the modern Internet environment, in the interests of encouraging proper use of correct domain names, it is often better to instead discourage all use/acceptance of short form names.)

Note that, as with all asterisk-in-place-of-component(s) probes, these probes are only made to the configuration file (legacy configuration) or  group (Unified Configuration), not to the domain database.

See also:
 * A rule to match any address
 * Rewrite rule patterns and tags