[galaxy-dev] Nucleotide vs Protein FASTA files

Hi all, For several tools it is useful to restrict input to just protein FASTA files, or just nucleotide FASTA files (or even just DNA or just RNA). Galaxy has the concept of file types, e.g. "tabular" or "fasta". Is there any way to add additional meta-data on top of this, or file sub-types? I remember asking James Taylor about this particular example (types of FASTA file) at a conference a few years ago (probably BOSC/ISMB), and I recall at the time he said there were no plans in this direction... is that still true? Thanks, Peter