# Extensions for handling hierarchical metadata records
#
# Peter N. Schweitzer (U.S. Geological Survey, Reston, VA 20192)
#
# Records are related by listing, in the Metadata_Lineage section
# of Metadata_Reference_Information, the records to which this one
# is related.  These records are specified using the elements
# Parent_Record and Child_Record.  Only one Parent_Record may be
# specified, but Child_Record may be repeated.
#
# Two additional elements are required, Record_Identifier_Type and
# Record_Combine_Method.
#
# Record_Identifier_Type gives an indication of how application software
# should interpret the values of Parent_Record and Child_Record elements.
# Possible values include "URL" or "database record identifier".  Note
# that a simple file name is a URL for practical purposes.  I need help
# from somebody who does RDBMS to give a robust way to specify a database
# record identifier.
#
# Record_Combine_Method indicates how a fuller record should be created
# and describes only the manner in which elements from this record
# should be combined with those of the parent record.  This applies only
# to cases in which the element in question is present in both.
# Possible values are "Augment" or "Replace".
#
# Metadata_Lineage is optional and repeatable in Metadata_Reference_Information.
# This permits parent-child relationships to be specified both as URLs
# and in some other format.  (Note that Record_Combine_Method should
# be expected to be the same in each instance of Metadata_Lineage if this
# is the reason for the repetition.)
#
# Metadata_Lineage =
# 	Record_Identifier_Type +
# 	Record_Combine_Method +
# 	0{Parent_Record}1 +
# 	0{Child_Record}n

Local:
	Name: Metadata_Lineage
	sgml: metalin
	parent: Metadata_Reference_Information
	child: Record_Identifier_Type
	child: Record_Combine_Method
	child: Parent_Record
	child: Child_Record

Local:
	Name: Record_Identifier_Type
	sgml: idtype
	parent: Metadata_Lineage

Local:
	Name: Record_Combine_Method
	sgml: combine
	parent: Metadata_Lineage

Local:
	Name: Parent_Record
	sgml: parent
	parent: Metadata_Lineage

Local:
	Name: Child_Record
	sgml: child
	parent: Metadata_Lineage

# end