The gas gas manual dates back to the early 1900's...
Always go with manufacturers specs. Gas Gas very likely holds some kind of record for most variations (brands) of suspension used on a dirtbike. Different models kitted with different specs, and different brands from year to year etc. Even in the current models there are 45mm OC Zokes, 48mm OC Sachs, 48mm Sachs with Ohlins TTX, and 48mm CC Zokes. Its no wonder some things are lost in the owners manual.