The links to identifier type are not consistent and in one page they are broken:

In this page http://build.fhir.org/identifier-registry.html 

the link to DL correctly resolves to http://terminology.hl7.org/1.0.0/CodeSystem-v2-0203.html#v2-0203-DL

but here http://build.fhir.org/identifier-registry.html

the link is http://build.fhir.org/v2/0203/index.html#DL