13.1.79 NilReasonType

Topic Version1Published11/11/2016
For StandardCOM v2.1

gml:NilReasonType defines a content model that allows recording of an explanation for a void value or other exception.

gml:NilReasonType is a union of the following enumerated values:

- inapplicable there is no value

- missing the correct value is not readily available to the sender of this data. Furthermore, a correct value may not exist

- template the value will be available later

- unknown the correct value is not known to, and not computable by, the sender of this data. However, a correct value probably exists

- withheld the value is not divulged

- other:text other brief explanation, where text is a string of two or more characters with no included spaces


- anyURI which should refer to a resource which describes the reason for the exception

A particular community may choose to assign more detailed semantics to the standard values provided. Alternatively, the URI method enables a specific or more complete explanation for the absence of a value to be provided elsewhere and indicated by-reference in an instance document.

gml:NilReasonType is used as a member of a union in a number of simple content types where it is necessary to permit a value from the NilReasonType union as an alternative to the primary type.

Table 13.1.79-1 Associations



From: NilReasonType.

To: anyURI



From: AssociationAttributeGroup.nilReason

To: NilReasonType