--- a/PresetMaps.wiki	Thu Nov 22 15:59:25 2018 +0000
+++ b/PresetMaps.wiki	Sat Dec 01 00:54:09 2018 +0000
@@ -68,7 +68,9 @@
   * As of 0.9.19+, map.png is optional if a mask.png is provided.  If there is no map.png, the theme will be used to decorate the map.  No objects will be added to white areas.  Use black if you want objects.
 
 ==== `preview.png` ====
-Preview image of the map. The preferred preview is created by simply downscaling your map. Please don't abuse the preview by adding things which don't actually exist in the map. Exceptions may apply for maps with unusual dimenions or other maps which are somehow special.
+Preview image of the map, usually a smaller version of `map.png`. This should really just be the preview, and nothing else. This file can normally be created by simply downscaling your `map.png`. The theme background should be not added.
+
+*Please don't abuse the preview! Don't add text, logos or other things which don't actually exist in the map.* Those just defeat the purpose of a preview. There might be a *few* exceptions, but those are rare.
 
   * Size: 256 × 128