Document the class mappings features
Signed-off-by: martin f. krafft <madduck@madduck.net>
diff --git a/doc/source/operations.rst b/doc/source/operations.rst
index 671b8b0..0bbf599 100644
--- a/doc/source/operations.rst
+++ b/doc/source/operations.rst
@@ -75,6 +75,23 @@
node into what has been accumulated during the processing of the classes, and
returns the final result.
+Wildcard/Regexp mappings
+------------------------
+Using the :doc:`configuration file <configfile>`, it is also possible to
+provide a list mappings between node names and classes. For instance::
+
+ class_mappings:
+ - \* default
+ - /^www\d+/ webserver
+ - \*.ch hosted@switzerland another_class_to_show_that_it_can_take_lists
+
+This will assign the ``default`` class to all nodes (make sure to escape
+a leading asterisk (\*) to keep YAML happy), ``webserver`` to all nodes named
+``www1`` or ``www999``, and ``hosted-in-switzerland`` to all nodes whose names
+end with ``.ch`` (again, note the escaped leading asterisk). Multiple classes
+can be assigned to each mapping by providing a space-separated list (class
+names cannot contain spaces anyway).
+
Parameter interpolation
------------------------
Parameters may reference each other, including deep references, e.g.::