http://gedcomx.org/IdentifierType

Enumeration of standard identifier types.

type	description
`http://gedcomx.org/Primary`	The primary identifier for the resource.
`http://gedcomx.org/Evidence`	An identifier for the evidence that supports the resource. For example, when a conclusion about a person is extracted, analyzed and evaluated atomically within the context of a single source, it takes the form of a (extracted) person conclusion, and the extracted conclusion may supply an identifier for the person. As all evidence for the person is gathered, the (working) person conclusion identifies the evidence used to support the conclusion by including each evidence identifier in the list of identifiers for the person.
`http://gedcomx.org/Deprecated`	An identifier that has been relegated, deprecated, or otherwise downgraded. This identifier is commonly used as the result of a merge when what was once a primary identifier for a person is no longer primary.
`http://gedcomx.org/Persistent`	An identifier that is considered to be a long-term persistent identifier. Applications that provide persistent identifiers are claiming that links to the resource using the identifier won't break.