•The word “identifier” can mean several
different things, e.g.:
•Labels
–Output
of numbering schemes (ISO TC46/SC9, others)
–e.g.
“3-540-40465-1” (an ISBN) [individual label]
–“ISBN”
(an ISO numbering identifier) [scheme]
–Registration
authority
•Specifications
[“Actionable” labels]
–Internet
infrastructure specifications (IETF, W3C)
–e.g.
URL, URN, URI (URI = Uniform Resource Identifier)
–“if
you follow this spec then you can make the label actionable …given the right tools…”
•Systems
–Labels,
following a specification, in a system
–e.g.
Bar code system, DOI system
–“if
you use this system, then the label IS actionable”
–Packaged
system offering
label + tools + business model
–A
packaged system is not essential, but is convenient