Big Gray Walln. 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 compilers, databases, multivendor networking, and programming tools. Recent (since VMS version 5) documentation comes with gray binders; under VMS version 4 the binders were orange (`big orange wall'), and under version 3 they were blue. See VMS. Often contracted to `Gray Wall'.