Are alpha characters used for field names valid in MARC records? When we do dumps of MARC records our ILS often dumps them with FMT and CAT field names. So not only do I have glorious 246 fields and 100 fields but I also have CAT fields and FMT fields. Are these features of my ILS -- extensions of the standard -- or really a part of MARC? Moreover, does something like Marc4J or MARC::Batch and friends deal with these alpha field names correctly? -- Eric Lease Morgan