Field Definitions are Available Here
Collection
string (80)
The type of the association whether an input type, or dependent type etc.
Dependent
/CollectionAssociations/CollectionAssociation/CollectionType
/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:aggregationInfo/gmd:MD_AggregateInformation/gmd:associationType/gmd:DS_AssociationTypeCode
Identification Information (ECHO)