When reading input or passing input from another program, the language processor also changes alphabetic characters to uppercase before processing them. To prevent translation to uppercase, use the PARSE instruction.
/************************** REXX ***********************************/
/* This REXX program gets the name of an animal from the input */
/* stream and sends it to the terminal. */
/*******************************************************************/
PULL animal /* Get the animal name.*/
SAY animal
TYRANNOSAURUS
PARSE PULL animal
TyRannOsauRus