diff --git a/XMLConfigReference.md b/XMLConfigReference.md
index e726586..a49d237 100644
--- a/XMLConfigReference.md
+++ b/XMLConfigReference.md
@@ -23,7 +23,8 @@ The Map object defines the master object of a mapnik configuration XML. It defin
   * *background-image*: Available in Mapnik2: use an image for the background instead of a color fill.
   * *font-directory*: Available in Mapnik2: pass a directory that contains fonts, which will automatically be registered if they end in ttf, otf, ttc, pfa, pfb, ttc, or dfont.
   * *srs*: Coordinate system in which the map is rendered (for instance '+proj=latlong+datum=WGS84' for a WGS84 Geographic coordinate system)
-  * *buffer-size*: Default 0; Good value is usually tile size/2 to help avoid cut labels. This influences envelope used by placement detector ( i.e. 'avoid_edges' parameter)
+  * *buffer-size*: Default 0; Good value is usually tile size/2 to help avoid cut labels. This influences envelope used by placement detector ( i.e. 'avoid_edges' parameter). Also set maximum-extent, otherwise you will get problems for bboxes near the borders of your map.
+  * *maximum-extent*: Set to maximum extent of (projected) map, ie. in coordinates of result map. For instance "-20037508.34, -20037508.34, 20037508.34, 20037508.34". See also [[BoundsClipping]].
   * *paths-from-xml*: Check if relative paths should be interpreted as relative to/from XML location (default is true)
   * *minimum-version*: Declare the minimum version of mapnik to be used with the stylesheet. Example: minimum-version="0.6.1". Will print a notice if you use an older mapnik version.