Things
Material, inanimate objects, mostly works of art, both preserved and unpreserved
Nature
Present taxonomy of biotic and abiotic resources
Words
Texts, both printed and handwritten
Actors
Persons, groups, and corporations, both contemporary and historical
Designs
Relationships among designs
Iconographies
Classification of iconographic subjects, primarily relying on ICONCLASS
Places
Map and list of localities and narrower spots, e.g. specific buildings, both contemporary and historical
Timelines
In preparation
Guidebook