This is a document issued to Shimano Dealers. You got two luxury ring binders resplendent in hand-tooled Naugahide - and every year your trusty local Shimano Distributor sent you a pack of pages to put in them. Each section covered a particular model and had a complete exploded diagram and part numbers for those parts that were available as spares. Handily, most parts explosions were coded with a date. Not quite so handily, your distributor rarely seemed to have the actual spares in stock - but good things come to those who wait. The point of listing spares for the Shimano Tourney TY05, and its like, also escaped me - the packaging for the spare part probably cost more that the whole derailleur.
This collection is from 1991.