An item

Basic URI: 
content://net.lp.collectionista.products/items
URI variants: 
For internal use only: content://net.lp.collectionista.products.items
For example: content://net.lp.collectionista.products/items/cd/music
For example (for internal use only): content://net.lp.collectionista.products.items.cd.music
MIME types: 
vnd.android.cursor.item/vnd.collectionista.product.item.*
For example: vnd.android.cursor.item/vnd.collectionista.product.item.cd.music
vnd.android.cursor.dir/vnd.collectionista.product.item.*
For example: vnd.android.cursor.dir/vnd.collectionista.product.item.cd.music
vnd.android.cursor.item/vnd.collectionista.product.item
vnd.android.cursor.dir/vnd.collectionista.product.item

MIME type for an item. An item that is part of a collection.

"vnd.android.cursor.item/vnd.collectionista.product.item" is a general MIME type for an item. Depending on "item" or "dir" a single item or a list of items.

Also specific MIME types exist for items of a specific type. An example is "vnd.android.cursor.item/vnd.collectionista.product.item.cd.music" for a music CD item. See other URIs (not all will be listed in this registry).

Originally for Collectionista, but every collection manager can use these.