Improve documentation

radicale/rights/from_file.py

@@ -15,6 +15,24 @@
 # You should have received a copy of the GNU General Public License
 # along with Radicale.  If not, see <http://www.gnu.org/licenses/>.
 
+"""
+Rights backend based on a regex-based file whose name is specified in the
+config (section "right", key "file").
+
+Authentication login is matched against the "user" key, and collection's path
+is matched against the "collection" key. You can use Python's ConfigParser
+interpolation values %(login)s and %(path)s. You can also get groups from the
+user regex in the collection with {0}, {1}, etc.
+
+For example, for the "user" key, ".+" means "authenticated user" and ".*"
+means "anybody" (including anonymous users).
+
+Section names are only used for naming the rule.
+
+Leading or ending slashes are trimmed from collection's path.
+
+"""
+
 import configparser
 import re