document repo URLs / archive location

docs/usage.rst

@@ -12,6 +12,76 @@ command in detail.
 General
 -------
 
+Repository URLs
+~~~~~~~~~~~~~~~
+
+**Local filesystem** (or locally mounted network filesystem):
+
+``/path/to/repo`` - filesystem path to repo directory, absolute path
+
+``path/to/repo`` - filesystem path to repo directory, relative path
+
+Also, stuff like ``~/path/to/repo`` or ``~other/path/to/repo`` works (this is
+expanded by your shell).
+
+
+**Remote repositories** accessed via ssh user@host:
+
+``user@host:/path/to/repo`` - remote repo, absolute path
+
+``ssh://user@host:port/path/to/repo`` - same, alternative syntax, port can be given
+
+
+**Remote repositories with relative pathes** can be given using this syntax:
+
+``user@host:path/to/repo`` - path relative to current directory
+
+``user@host:~/path/to/repo`` - path relative to user's home directory
+
+``user@host:~other/path/to/repo`` - path relative to other's home directory
+
+Note: giving ``user@host:/./path/to/repo`` or ``user@host:/~/path/to/repo`` or
+``user@host:/~other/path/to/repo``is also supported, but not required here.
+
+
+**Remote repositories with relative pathes, alternative syntax with port**:
+
+``ssh://user@host:port/./path/to/repo`` - path relative to current directory
+
+``ssh://user@host:port/~/path/to/repo`` - path relative to user's home directory
+
+``ssh://user@host:port/~other/path/to/repo`` - path relative to other's home directory
+
+
+If you frequently need the same repo URL, it is a good idea to set the
+``BORG_REPO`` environment variable to set a default for the repo URL:
+
+::
+
+    export BORG_REPO='ssh://user@host:port/path/to/repo'
+
+Then just leave away the repo URL if only a repo URL is needed and you want
+to use the default - it will be read from BORG_REPO then.
+
+Use ``::`` syntax to give the repo URL when syntax requires giving a positional
+argument for the repo (e.g. ``borg mount :: /mnt``).
+
+
+Repository / Archive Locations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Many commands want either a repository (just give the repo URL, see above) or
+an archive location, which is a repo URL followed by ``::archive_name``.
+
+Archive names must not contain the ``/`` (slash) character. For simplicity,
+maybe also avoid blanks or other characters that have special meaning on the
+shell or in a filesystem (borg mount will use the archive name as directory
+name).
+
+If you have set BORG_REPO (see above) and an archive location is needed, use
+``::archive_name`` - the repo URL part is then read from BORG_REPO.
+
+
 Type of log output
 ~~~~~~~~~~~~~~~~~~