Jeff's code is great and use a clever way to remove any multiple instances of the unwanted items.
Just to illustrate that there's often more than one way to do things in JSL: here's an alternative approach using Associative Arrays.
(Note, all multiples would be removed)
MYLIST = {:empty, :empty2, :Name("A:k"), :Name("A:m"), :Name("A:x"), :Name("A:y"), :NA, :Name("D:3"), :Name("D:6"), :Name("D:8")};
DELCOLS = {:empty, :empty2};
// Remove DELCOLS from MYLIST. Retains original order of items.
AA = Associative Array(MYLIST, 1 :: N Items(MYLIST));
MYLIST = (AA << Remove(Associative Array(DELCOLS)) << get keys)[Rank(AA << get values)];
// If order is not important, this simpler version works (items sorted alphabetically)
MYLIST_sorted = Associative Array(MYLIST) << Remove(Associative Array(DELCOLS)) << get keys;
Show(MYLIST, MYLIST_sorted);