%F — original filename (no extension)
%TITLE — Title field
%COMPOSER — Composer field
%CLAST — composer last name
%CFI — composer first initial
%CLASTFI — composer last name + first initial
%YY — year (2-digit)
%YYYY — year (4-digit)
%MM — month (01-12)
%DD — day (01-31)
%YYMMDD — date (2-digit year)
%YYYYMMDD — date (4-digit year)
%% — literal %