As web archives' holdings grow, archivists subdivide them into collections so
they are easier to understand and manage. In this work, we review the
collection structures of eight web archive platforms: : Archive-It, Conifer,
the Croatian Web Archive (HAW), the Internet Archive's user account web
archives, Library of Congress (LC), PANDORA, Trove, and the UK Web Archive
(UKWA). We note a plethora of different approaches to web archive collection
structures. Some web archive collections support sub-collections and some
permit embargoes. Curatorial decisions may be attributed to a single
organization or many. Archived web pages are known by many names: mementos,
copies, captures, or snapshots. Some platforms restrict a memento to a single
collection and others allow mementos to cross collections. Knowledge of
collection structures has implications for many different applications and
users. Visitors will need to understand how to navigate collections. Future
archivists will need to understand what options are available for designing
collections. Platform designers need it to know what possibilities exist. The
developers of tools that consume collections need to understand collection
structures so they can meet the needs of their users.Comment: 5 figures, 16 pages, accepted for publication at TPDL 202