The rules file specification language that BART uses is the standard UNIX quoting syntax for representing nonstandard file names. Embedded tab, space, newline, or special characters are encoded in their octal forms to enable the tool to read file names. This nonuniform quoting syntax prevents certain file names, such as those containing an embedded carriage return, from being processed correctly in a command pipeline. The rules specification language allows the expression of complex file name filtering criteria that would be difficult and inefficient to describe by using shell syntax alone.
For more information about the BART rules file or the quoting syntax used by BART, see the bart_rules(4) man page.