The type of content available in a pack is determined by its Category. The selected Category also determines which tab the content pack will appear under.
Layer Packs
spatial layers
layer groups
Geometry
sections (geometries)
usages
blocks & block definitions
flows & transform presets
related property definitions
Usages
usages
related property definitions
Flows
flows
transform/input presets
usages
blocks & block definitions
sections (geometries)
related property definitions
Analytics
measures
categories (auto)
tabs (auto)
usages
grouping
layers/layer groups
related property definitions
Reports
reports (app)
report pages
report elements
Blocks
Blocks
Block Definitions
Usages (if nested in the Block definition)
property definitions (if nested in the Block definition)
flows (if nested in the Block definition)
Bundles
Anything and everything!