That's telling you that for short SORT fields, you can use DFSORT's VLSHRT option, e.g.
(VLSCMP is only for short INCLUDE/OMIT fields.)
is this possible to sum on a non numeric field
It depends on what the "non-numeric field" values look like. If they're actually numbers, e.g. '1234', you can use ZD to SUM on them. If they're something else, you need to show what they look like and explain what you want for the result of "summing" them.
VLSHRT can be used with SORT, MERGE, INCLUDE, OMIT and/or SUM.
My SUM challenge is with letters not numbers
Oh, then you really don't want to SUM anything - you just want to eliminate duplicates. That would be:
If you're not familiar with DFSORT and DFSORT's ICETOOL, I'd suggest reading through "z/OS DFSORT: Getting Started". It's an excellent tutorial, with lots of examples, that will show you how to use DFSORT, DFSORT's ICETOOL and DFSORT Symbols. You can access it online, along with all of the other DFSORT books, from: