One of the aims of Yagsbook is to enable RPG information to be defined in a way that can be used by other people. To this end, one part of the Yagsbook project is to define general equipment lists that can be used freely in any game system.
Equipment is available by genre and technology level.
Genre can be Modern or Low Tech.
Items have a technology level defined, which gives a guide to when an item was introduced.
TLs beyond 8 are not defined, since these would have to be specific to a given science fiction campaign.