info-vax@ucbvax.ARPA (02/14/85)
From: lionel%eludom.DEC@decwrl.ARPA (Steve Lionel) The use of the "@" character in the middle of DCL commands is documented in section 1.4 of the "Guide to Using DCL and Command Procedures on VAX/VMS" (VMS V4 edition). I believe it was implemented for compatibility with RSX, and has been there since VMS V1.