Each exit subfunction has a different parameter list. All RXSTRING exit subfunction parameters are passed as null-terminated RXSTRINGs. The RXSTRING value may also contain null characters.
For some exit subfunctions, the exit handler may return an RXSTRING character result in the parameter list. The interpreter provides a default 256-byte RXSTRING for the result string. If the result is longer than 256 bytes, a new RXSTRING can be allocated using DosAllocMem. The REXX interpreter returns the RXSTRING storage for the exit handler.