DataCite Metadata Schema v4.4 Standard Values for Unknown Information

The following are a set of standard values that may be used when mandatory property values are not available for various reasons.

Examples of usage:

:unas :null
:unactemporarily inaccessible
:unalunallowed, suppressed intentionally
:unapnot applicable, makes no sense
:unasvalue unassigned (e.g., Untitled)
:unavvalue unavailable, possibly unknown
:unknknown to be unknown (e.g., Anonymous, Inconnue)
:nonenever had a value, never will
:nullexplicitly and meaningfully empty
:tbato be assigned or announced later
:etaltoo numerous to list (et alia)