I'm sure that this is something that you will have come across in your time as fellow researchers: how best to use CIL. For instance, I'm using a copy of CIL 4, Supplement 3 to include incriptions and references relevant to my research, but my university's copies are ages old as it dates from the turn of the nineteeth to twentieth century.
Of course, there will have been more entries made since this version was published and these I can get by interlibrary loan. But does anyone know of any online sources for searching specific entries (ie., by region, subject etc)? Or have any general tips? I may have missed a simple bit in the understanding of how CIL works, so I'd be grateful for even the most basic of information!