I am struggling with the extend: left right normal and reverse, they do not seem to be doing what I would expect or as described at http://therion.speleo.sk/wiki/doku.php?id=tfc:321 therion 5.3.7 on debian wheezy These have been generated from the th file attached, which was an import from pocket topo. The file is as I needed it to work, for the below, remove all extend commands and then only add before the first line as shown. which is how PocketTopo export comes in. Adding it to the centreline -extend ##### seems to have the same effect as below. They are all viewed in the pdf, as I really have nothing else at the moment :( Also it appears that the extend command, moves all the splays in the same direction, which I guess is how survex intended it, but this is different from the PocketTopo, that treats slays differently and to me more sensibly (well in most situations). But this is not really that important as the splays generated by therion are not used for the PocketTopo image import. Noextend.pdf as it says has all the extend commands removed, so I would expect everything to go right, apart fro, 2.0 to 2.1 goes left case1.pdf So add extend right before the line extend right 2.0 - 260.00 11.60 2.610 So the legs go right then left, right,left right right...right, left, leftleft??? case2.pdf (file not included as it is the same as Noextend) extend normal 2.0 - 260.00 11.60 2.610 should be the same as right (unless I am missing a subtle difference) and no commands at all. It is the same as Noextend.pdf but different from case 1 case3.pdf extend left 2.0 - 260.00 11.60 2.610 opposite of right so at least consistent left, right, left, right, left, left ... left right, right case4.pdf extend reverse 2.0 - 260.00 11.60 2.610 consistent again: opposite of normal, but the first leg goes right instead of left and the they all go left So normal and reverse seem to work apart from the first leg, but left and right are doing something strange to the first few legs Using the commands in anywhere else in a linear part of the centreline mostly seems to work fine, and as expected, continuing down the consecutive numbering at a branch fine (but this could also be the order of the data in the file). However, left and right are less reliable than normal and reverse?? But not worked out a pattern yet. Other branches it is less clear for and this email is long enough Andrew