s starting with "#" act as comments in the ignore file.
      To ignore patterns that begin with that character, use the "RE:" prefix.

    :Examples:
        Ignore the top level Makefile::

            brz ignore ./Makefile

        Ignore .class files in all directories...::

            brz ignore "*.class"

        ...but do not ignore "special.class"::

            brz ignore "!special.class"

        Ignore files whose name begins with the "#" character::

            brz ignore "RE:^#"

        Ignore .o files under the lib directory::

            brz ignore "lib/**/*.o"

        Ignore .o files under the lib directory::

            brz ignore "RE:lib/.*\.o"

        Ignore everything but the "debian" toplevel directory::

            brz ignore "RE:(?!debian/).*"

        Ignore everything except the "local" toplevel directory,
        but always ignore autosave files ending in ~, even under local/::

            brz ignore "*"
            brz ignore "!./local"
            brz ignore "!!*~"
    )