Specifying UPPER on any of the PARSE instructions converts lowercase a-z to uppercase A-Z before parsing.
The ARG instruction is a short form of PARSE UPPER ARG. The PULL instruction is a short form of PARSE UPPER PULL. If you do not desire uppercase translation, use PARSE ARG instead of ARG or PARSE UPPER ARG, and PARSE PULL instead of PULL or PARSE UPPER PULL.
Specifying LOWER on any of the PARSE instructions converts uppercase A-Z to lowercase a-z before parsing.
Specifying CASELESS means the comparisons during parsing are independent of the case--that is, a letter in uppercase is equal to the same letter in lowercase.