Evolution of a Bottle
The caps from the very old standard-shaped bottles were very different:
The logos on the standard shaped bottles have also changed:
Some very old collections had differently shaped bottles as well, for instance the blah blah collections: oval bottle pics & shiny caps
Some very old colelctions also had the collection name on them, whether in oval or round bottles:
Silver caps usually indicate a special collection like a holographic. Also, the Pure Platinum collection had silver caps.
Some newer, "special" polishes have the collection name on them. (Transitions, crackle, magnetic)