update

docs/building/sources/grib.rst

@@ -20,12 +20,12 @@ wildcards_:
 .. literalinclude:: yaml/grib3.yaml
    :language: yaml
 
-You can also use the requested `date` to build the filenames.
-It the GRIB files containing the requested data are named according to
-the following pattern:
-
-   ``/path/to/YYYY/MM)/YYYYMMDDHH.grib``
-
+You can also use the requested `date` to build the filenames. For
+example It the GRIB files containing the requested data are named
+according to the following pattern:
+``/path/to/YYYY/MM)/YYYYMMDDHH.grib`` with `YYYY` being the year, `MM`
+the month, `DD` the day and `HH` the hour, you can use the following
+configuration:
 
 .. literalinclude:: yaml/grib4.yaml
    :language: yaml