Merge branch 'criteria'

schema.rst

@@ -172,53 +172,3 @@ Notes
 
 .. [#schemaversion] The value of `SchemaVersion` is defined to be
    equal to the version number for each release version of the schema.
-
-Criteria for adding and classifying properties
-----------------------------------------------
-
-This section formulates criteria for adding properties to the schema
-and for classifying them as mandatory, recommended, or optional.
-These criteria should be taken as guidelines to consider in the
-discussion, but not as strict rules.
-
-Criteria for adding properties
-..............................
-
-A property should be included in the schema, if an application
-requires to store some piece of information in the metadata that
-cannot be represented appropriately in any other already existing
-property.  Otherwise, the schema would become useless for that
-application.
-
-On the other hand, redundancy should be avoided.  Ideally, there
-should be only one place in the schema for any given piece of
-information.
-
-Criteria for classifying the obligation of properties
-.....................................................
-
-A property should be classified as mandatory, if either
-
-- an PIDINST does not make sense at all without that property, or if
-
-- an application requires to find this piece of information in third
-  party PIDINST metadata.
-
-It should be taken into account that each mandatory property creates
-an additional burden for metadata providers.  So this classification
-should be used carefully.  If any application is not able to provide
-meaningful values for the property, this should be taken as a strong
-hint that the classification as mandatory is not appropriate.  On the
-other hand, the application may fall back on “Standard values for
-unknown information” (see Appendix 3 in the `DataCite 4.1 Metadata
-Schema Documentation`_), so that applications may put into mandatory
-attributes if this piece of information is not available.
-
-A property that is not mandatory should be classified as recommended
-if this piece of information is considered to be general useful in
-third party PIDINST metadata for many applications.
-
-Properties that are neither mandatory nor recommended are optional.
-
-
-.. _DataCite 4.1 Metadata Schema Documentation: https://schema.datacite.org/meta/kernel-4.1/