Source : Free On-Line Dictionary of Computing

Big Gray Wall
     
         What faces a {VMS} user searching for documentation.
        A full VMS kit comes on a pallet, the documentation taking up
        around 15 feet of shelf space before the addition of layered
        products such as {compiler}s, {database}s, multi-vendor
        networking, and programming tools.  Recent (since VMS version
        5) DEC documentation comes with grey binders; under VMS
        version 4 the binders were orange and under version 3 they
        were blue.  Often contracted to "Gray Wall".
     
        [{Jargon File}]
     
        (1995-03-07)