help/patterns.txt

keyword: clarify object of backwards compatibility

Mercurial accepts several notations for identifying one or more files
at a time.

By default, Mercurial treats filenames as shell-style extended glob
patterns.

Alternate pattern notations must be specified explicitly.

To use a plain path name without any pattern matching, start it with
``path:``. These path names must completely match starting at the
current repository root.

To use an extended glob, start a name with ``glob:``. Globs are rooted
at the current directory; a glob such as ``*.c`` will only match files
in the current directory ending with ``.c``.

The supported glob syntax extensions are ``**`` to match any string
across path separators and ``{a,b}`` to mean "a or b".

To use a Perl/Python regular expression, start a name with ``re:``.
Regexp pattern matching is anchored at the root of the repository.

Plain examples::

  path:foo/bar   a name bar in a directory named foo in the root
                 of the repository
  path:path:name a file or directory named "path:name"

Glob examples::

  glob:*.c       any name ending in ".c" in the current directory
  *.c            any name ending in ".c" in the current directory
  **.c           any name ending in ".c" in any subdirectory of the
                 current directory including itself.
  foo/*.c        any name ending in ".c" in the directory foo
  foo/**.c       any name ending in ".c" in any subdirectory of foo
                 including itself.

Regexp examples::

  re:.*\.c$      any name ending in ".c", anywhere in the repository