Dear Jane I think what I am trying to say is,that I don't have to know which DED- the LDS catalogue has worked it out for me. For example- I have recently been asked to look for a townland in co.Down- Kilkinamurry . I'm way out of my area here- have no knowledge of this county. So,I find the PARISH on _www.seanruad_ (http://www.seanruad) and it's Garvaghy. So type Garvaghy onto the family search website -PLACE SEARCH. Following through I get 1901/1911 census ,CLICK Film notes: Note Location Film 1911 Balloolymore D.E.D. 5/1-7 FHL BRITISH Film 827675 1901 Garvaghy D.E.D. 14/1-7 FHL BRITISH Film 827680 Item 1 1911 Balloolymore D.E.D. 5/1-4 Townlands: Ballooly, Balloolymore, Castlevennon, Killaney FHL BRITISH Film 2082444 Item 2 1911 Balloolymore D.E.D. 5/5-7 Townlands: Knockgorm, Shanrod, Tullyorior FHL BRITISH Film 2082445 Item 1 1911 Garvaghy D.E.D. 14/1-5 Townlands: Carnew, Enagh, Fedany, Garvaghy, Tullinisky FHL BRITISH Film 2092885 Item 2 1911 Garvaghy D.E.D. 14/6-7 Townlands: Corbally, Kilkinamurry VAULT BRITISH Film 2092682 Item 1 If you look at the 1911 entry,Kilkinamurry is listed as no.7 in Garvaghy DED 14 (Corbally is no.6). To work out the film no.I need in the 1901,I look for Garvaghy DED 14,townland no.7. The ITEM no. shows where it is on the film- on the 1911 the 2 townlands in Garvaghy will be the FIRST thing on the film.(There can be up to about 20 items on a film,but it varies enormously according to subject matter.) If I want to know what else is on that same film,I type the film no.into FILM/FICHE search on the LDS catalogue ( in this case, 4 townlands in Dromore parish). In this particular example,there's no real test,as the choices are minimal,but in a more complex example,the same principle would apply. In other words,if you took a copy of the LDS catalogue to the Dublin Archives with you,you would be able to determine the DED straightaway ( assuming you knew the parish.) I presume on occasion,a townland may move from one parish to another,and consequently come into a different DED from one census to another,probably more so in town than country.So far,I haven't met that situation,so I don't know if the LDS system holds up in those circumstances.I order a lot of census films working for the LDS and I have never had a problem (yet!) The last time I ordered a census in Dublin,they handed me the original books! Guess things have changed a bit? Just out of interest,I have this notion in my head that the LDS did the filming for the Archives. Is that likely? Just that the same films are missing from the 1911 Galway census for both the LDS and Galway Library.Coincidence? Cathy