The forum clearly says D2:R classic trading. "D2:R" being the key.
D2: Classic trading would fit better would it not?
and the ROTW warlock doesnt seem to have any non ladder trading if thats the case?
D2R Classic already exists and its the Classic version ( without Lord of Dest expansion which means no charms/runes etc )
D2R Expansion already exists and its the ( Lord of Dest ) Expansion that has NOT been upgraded to ROTW
D2R RoTW exists as well as NL and Ladder subs for both Cores.
Classic is Classic, it's always been this way.
To answer your last question the ROTW Warlock Non-Ladder forum is here:
https://forums.d2jsp.org/forum.php?f=268 ( this is Softcore although Hardcore also exists ).