Comma is not allowed in SET values in a field definition:
SP variables erroneously allow commas:
Notice, the 'a,b' value is ignored.
Inserting assigning 'a,b' to the variable a results in the numeric value 3, which is a bit combination of 1 for 'a' and 2 for 'b'.
Commas should be disallowed in values for SP SET variables.