Does anyone have an explanation for the what and how of 'map-level' as it relates to maps as described in this extract from Pg 31 of the Therion Book 5.2.14. preview <above/below> <other map id> will put the outline of the other map in the specified preview position relative to the current map. Preview is displayed only if the map is in the map-level level as specified by the select command. Use the revise command if you want to add maps from higher levels to the preview. I have only ever managed to create previews of maps in the very simplest of cases (except I'm not sure exactly what constitutes a simple case - the ones that don't work seem to be quite straight forward, and not much different to those that don't work ). I think it may relate to 'map-level'. I have asked on this forum about a year ago, but alas I still have not resolved this. I have not been able to comprehend the explanations in the wiki (which is similar to the Therion book extract above). I think the first step to working it out might be to understand what a map-level is. I think it is not referring to the layering of scraps or maps within a map. Maybe it is the level of the map in the hierarchy displayed in the XTherion Compiler window 'Map Structure' panel? If so how are they numbered? How to determine the map-level of any given map? Top level 0 or 1? Bottom level 0 or 1? How would I use 'revise' to change the map-level of a map to enable a preview to be displayed? My attempts to change something simple like a map -title have all failed, so there must be something fundamental that I'm not understanding. Any assistance appreciated. Bruce