The function TRANSLATE called without the tab_in and tab_out parameter to translate the input string to uppercase only handles the characters from A to Z. National characters (like German "Umlaute") are not converted. Note also that there is no function to convert a string to lowercase.
(see Uppercase & Lowercase including German "Umlaute" for a possible solution of this problem. Note that the REXXUTIL DLL from Object-Oriented REXX contains a function for country-dependent uppercase translations)