[GraemeJ]

To repeat something I said in a similar, earlier, thread; I work with a lot of different vocalists (who all do much the same repertoire, but not always the same key and/or arrangement). I found it best to name the file "whatever tune - key.pdf". I then use the 'Custom' field to further differentiate (in my case, usually by vocalist). When displayed on the tablet, I see:

whatever tune - key [vocalist]

That way, all the versions are together, e.g.;

My Romance - Am [Elena]
My Romance - Gm [Nicole]
My Romance - Am [SueK]
and so on.

The last one is a different arrangement to the other Am version.

This means I can quickly select by the vocalist (assuming it's someone I work with regularly) or by the key required.

My experience has been that finding a part is so quick, it doesn't really matter if you suddenly need something that's not in a setlist or collection. I have some 1,500 individual charts (amounting to the best part of 2,000 pages) and I can still find any one of them much quicker than my paper-based colleagues .