For Identifiers (just the complete URI and local part, not about mechanisms)

#permanent

#permanently resolve to a digital object

#unique within our PID system without the DNS name portion of the

#URL

#works with existing systems

#resolvable through a web browser

#Simplicity

#support for a local namespace prefix and an identifier part

#support for opaque identifiers

#Local part should not be Cornell branded

#may be surrogate for physical object

#should be short

#should be easy to copy by hand

For Resolver and System

#Supports billions of identifiers

#Robust architecture

#Robust implementation

#ability to request metadata about the identifier

#lightweight understanding of identifier equivalence

#should be easily discoverable by Google

#integrate well with the web architecture

#vitality checking

#Need to avoid unbounded generation of surrogate persistent identifiers

#PID corresponding to every Cornell NetID

#useful error when check digit is wrong

Governance Issues

#Requires payment to external organization

#Can continue resolve IDs in absence of external organization