I don't know anything about z390, but FWIW z/OS does not support 5/6/7-byte relocatable adcons (let alone use of 5 through 8 on ALn but they are supported on ADLn). Use of ADL5/6/7 is detected by the binder with the message: IEW2353E 243F SECTION TEST CONTAINS INVALID DATA. ERROR CODE IS 250008.
where 250008 - RLD contains an invalid length field. Supported lengths are 2, 3, 4, and 8, where 8 is allowed only for type loader token. <<I'm not confident that "where 8 is allowed only for type loader token" is correct. I'll inquire>> z/OS has never, to my knowledge, supported 1-byte relocatable adcons. And of course use of a length-2 RLD is kind of questionable (unless a truncated value is what you are going after). Peter Relson z/OS Core Technology Design
