I am starting the tedious process of migrating a large dataset from Survex to Therion. Now would therefore seem the right time to start converting the co-ordinate system that is used. The data is for Co. Clare in Ireland and previously all entrances and fixed points were listed in Irish Grid. The Irish are changing this to ITM (Irish Transverse Mercator) and I would like this to be the system that we use as it is what will appear on their maps etc. I am assuming that it is not supported by Therion. I cannot find an EPSG number that specifically relates to this. The IOS website talks about their system being compatible with ETRF89, for Europe but that is the nearest indication I get. Can anyone tell me what the correct EPSG number might be or is it possible for ITM to be built into Therion as an option? Graham --- graham.mullan@coly.org.uk 0117 9502556 or 07887 637064 (or try 0844 2327803)