Hi, I've just looked at the "library" option and saw that it is an SQLite database. I think that maybe it could be nice to get a key value from library available as a function (that we can use to tag a file), for example the "rowid" or "id" fields in the "mtfile" table (not sure that this is the "right" table).
This could be very usefull to import tags from a text file just using this key value as identifier and not have to worry about the sequential order, or a more "absolute" link than %_filename_ext% or %_path% (if you changed or renamed the files between operations).
Great program (very happy with, monthly contributor).
This would also mean that the function to import from text files has to be changed as right now it either uses the sequence of records or the filename but no database id which would not be there if you have switched off the library function.