[EMBOSS] Question about make use of multiple fields indexing by dbxfasta or dbxflat

[Jean Mao]

Hello,

I need to index swissprot data file from uniprot.org. They have two formats : fasta and flat available. I understand I can specify fields to be indexed. And there are more fields can be specified if using flat file with dbxflat. However, I am not sure how many programs in EMBOSS package will be benefit from specifying extra fields other than acc and id except 'seqret'? Could someone let me know how to find the answer? Thanks you very much in advance.

Jean