Wildcards in Email Addresses 
Wildcards can appear in the name or domain sections
of an email address. The following are valid examples:
-
name@*: Valid representation of the whole name.
-
*@domain.tld, name@*.tld: Valid representation of the whole name or the domain (not the top level domain (TLD)).
-
*@*.tld: Valid representation of both the name and the domain (not the TLD).
Wildcards cannot appear in a subdomain or the top-level domain. Wildcards also cannot
appear with
other letters; they must appear alone. The following are invalid examples:
-
name@domain.*.tld: Invalid representation of a subdomain.
-
name@domain.*: Invalid representation of a TLD.
-
*name@domain.tld: Invalid use in conjunction with a name.
Wildcards in File Names
You can use wildcard characters in file names the same way you can use
them in email addresses. Use an asterisk in the name or the extension sections of
a file
name, but not in conjunction with a partial name or extension. The following are valid
examples:
-
*.*: Valid representation of all files.
-
*.extension: Valid representation of all files of a certain extension.
-
name.*: Valid representation of files with a specific name but with any extension.
-
*name.*: Valid representation of a name.
-
name.*extension: Valid representation of an extension.