In 1995 there is a photo of the decks labelled VT0 and VT3, VT1 was the Umatic that no one used and VT2 was the VHS or what later became the SVHS. So when did the ident system change?
I joined in October 1996, and they were certainly letters by then. The only flirt with numbers I recall was when I bought a pile of identical VHS recorders for tape copying, TS1/TS2/TS3 ('the stack' or 'tape suite' as you prefer) Sprow 07:57, 31 May 2007 (BST)