Tarquin, David The results of our little quiz made me uneasy, so I found an old test project that I believe is structured like Tarquin's, a pattern I call 'scrap and map definitions - inside trip file - inside survey' SAMD-ITF-IS. The outcome I feared (due to my large collection of projects structured differently) is that map-connections with multi-level offsets would work just fine with SAMD-ITF-IS. That has not been the case, I have the same (I think) behaviour with this test project as I have with my other projects. So perhaps a degree of relief but still a mystery to resolve. With my test project: * Offsets work OK. * Offsets of offsets (level 2 offsets) work just fine so long as the most deeply nested offset map is comprised of scraps (and not maps). * Offsets of offsets (level 2 offsets) do not work (connection emanates from grandparent, not the parent) if the most deeply nested offset map is comprised of maps (a necessary prerequisite when preparing for the third level of offsetting). * Offsets of offsets of offsets (level 3 offsets) map-connections correctly emanate from their parent level 2 offset map, but the level 2 map-connection continues to incorrectly emanate from its grandparent. I have not progressed this to a fourth level, brain is starting to hurt and I ran out of scraps associated with the particular sub-survey that I picked on. Re-reading Tarquin's last email mentioning sub-sub-sub-surveys, I wonder if we are at cross purposes a little (or Tarquin is using 'survey' loosely to refer also to maps). In my example below (which I think is structured like Tarquin's) there are two surveys (1 and 2) and a parent cave survey that contains those two surveys, so only two levels of survey. However I have created three levels of map which offset correctly. When I create a fourth level of map in preparation for 3 levels of offset, the map-connection breaks. The code examples below show only to the level 2 and level 3 offset maps, and these are the maps on the left hand side of the diagrams, as annotated. Offset of offset is OK like this map 1-BottomUpPlan-Bottom \ -projection plan 1-BottomUpPlan-s2 break 1-BottomUpPlan-s1 #bottom terminal chamber endmap 1-BottomUpPlan-Bottom Offset of offset is not OK when same as above but map-of-scraps is split into map-of-maps that references maps-of-scraps ##Setup for OffsetLevel 3 map 1-BottomUpPlan-Bottom \ -projection plan 1-BottomUpPlan-B2 # break 1-BottomUpPlan-B1 endmap 1-BottomUpPlan-Bottom map 1-BottomUpPlan-B2 \ -projection plan 1-BottomUpPlan-s2 endmap 1-BottomUpPlan-B2 map 1-BottomUpPlan-B1 \ -projection plan 1-BottomUpPlan-s1 #bottom terminal chamber endmap 1-BottomUpPlan-B1 Offset of offset of offset is OK BUT its parent is not (as above) ##Setup for OffsetLevel 3 map 1-BottomUpPlan-Bottom \ -projection plan 1-BottomUpPlan-B2 # break 1-BottomUpPlan-B1 [0 10] below #OffsetLevel 3 endmap 1-BottomUpPlan-Bottom map 1-BottomUpPlan-B2 \ -projection plan 1-BottomUpPlan-s2 endmap 1-BottomUpPlan-B2 map 1-BottomUpPlan-B1 \ -projection plan 1-BottomUpPlan-s1 #bottom terminal chamber endmap 1-BottomUpPlan-B1 For what it is worth, here is the overall survey file, consistent with my SAMD-ITF-IS pattern: survey Cave map CavePlan -projection plan 2-EntrancePlan@2 1-BottomUpPlan@1 [0 -20] below #OffsetLevel 1 endmap CavePlan input 1-BottomUp.th input 2-Entrance.th centreline equate 1.4@1 1.4@2 endcentreline endsurvey Cave So Tarquin, Can you pick any fundamnetal differences? Are we doing the same things? Are we talking about the same things?