Explanation

During a file backup request, this optional parameter specifies files or directories to be excluded from backup processing. The <exclude_criteria> is a comma-separated list of filename patterns or directory names.

Filename patterns that are specified in the exclude list can contain any valid filename characters. Wildcard characters are the question mark (?) and asterisk (*).

The forward slash character is not allowed in the filename pattern.
If the pattern file contains any of the specific ?, *, or \ characters, the backslash character (\) must be used to escape that character to indicate it is not a wildcard. For example, \?, \*, or \\).
An asterisk (*) can be used to match any number of characters within a file name. An asterisk can be used at any position in the pattern. A second asterisk can also be used at the end of the pattern to that indicate any number of characters after the pattern is acceptable.
A question mark (?) can be used to represent any single character in the file name. Multiple question mark characters are allowed.

If the requested filename pattern does not include any wildcard characters, then that exact name is used to compare with files that are found in the subdirectories processed.

Directory names that are specified in the exclude list must end in a forward slash character. If the directory name begins with a forward slash character, then it is considered to be an absolute path. If the directory name does not begin with a forward slash character, it is considered to be a relative path that begins at the directory that is requested on the command.