Citation relationships are normally treated simply as the links between citing and cited entities. In this presentation, given at PIDapalooza2018 in Gerona, Spain on 24 January 2018, I give an alternative richer view, which is to regard citations as data entities in their own right. This permits us to endow the Citations with PROPERTIES
has start date (publication date of citing work)
has citation timespan
has type
has persistent identifier
etc.
I propose and describe the Open Citation Identifier (OCI), a new PID for citations, and a new resolution service for OCIs created by OpenCitations.