¡PURLs
lGood for small, local solutions
lSingle level indirection
l
¡DOI
lMultiple, hierarchical layers of indirection
lPurpose:
¡Actionable identifiers to content
¡Resolution to multiple items of current state data
lNotably including location(s) and metadata
¡
¡OpenURL
lPurpose: solves appropriate copy problem
lSelects between multiple items returned by DOI