Collection Roles

The Readium Web Publication Manifest specification defines the following roles for collections in its main specification document and extensions:

Core Roles

Role	Definition	Compact Collection?	Required?	Reference
`readingOrder`	Identifies a list of resources in reading order for the publication.	Yes	Yes	Main Specification
`resources`	Identifies resources that are necessary for rendering the publication.	Yes	No	Main Specification
`toc`	Identifies the collection that contains a table of contents.	Yes	No	Main Specification

Role	Definition	Compact Collection?	Required?	Reference
`landmarks`	Identifies the collection that contains a list of points of interest.	Yes	No	EPUB Profile
`loa`	Identifies the collection that contains a list of audio resources.	Yes	No	EPUB Profile
`loi`	Identifies the collection that contains a list of illustrations.	Yes	No	EPUB Profile
`lot`	Identifies the collection that contains a list of tables.	Yes	No	EPUB Profile
`lov`	Identifies the collection that contains a list of videos.	Yes	No	EPUB Profile
`pageList`	Identifies the collection that contains a list of pages.	Yes	No	EPUB Profile

While OPDS itself is not an extension of the Readium Web Publication Manifest, it shares the same abstract model and syntax.

OPDS 2.0 catalogs can also contain Web Publications as defined by the Readium Web Publication Manifest.

For these reasons, it feels relevant to list the collection roles that are introduced in this related specification.

Role	Definition	Compact Collection?	Required?	Reference
`navigation`	An ordered list of links meant to browse a catalog in depth.	Yes	No	OPDS 2.0
`publications`	Contains a list of publications.	No	No	OPDS 2.0
`images`	Visual representations for a publication.	Yes	No	OPDS 2.0
`facets`	Links meant to obtain a sub-set of the current list of publications, or the same list in a different order.	No	No	OPDS 2.0
`groups`	Structural element in a catalog meant to contain `navigation` or `publications` collections.	No	No	OPDS 2.0