This case-insensitive code system http://hl7.org/fhir/uv/pocd/CodeSystem/kind-of-relation defines the following codes:

Code	Display	Definition
Rcm	Recommendation	The METRIC is a recommendation for the containment tree entries defined in ./pm:Relation/@Entries
PS	Presetting	Presetting. This METRIC is a presetting for the containment tree entries defined in ./pm:Relation/@Entries.
SST	Set of summary statistics	The METRIC is part of a set of summary statistics for a sample where other METRICs that belong to the summary statistics are defined in ./pm:Relation/@Entries.
ECE	Effect on containment tree entries	When changed, the METRIC has an effect on the containment tree entries defined in ./pm:Relation/@Entries. If Kind is ECE, ./pm:Relation/pm:Code SHOULD be set to classify the effect.
DCE	Derived from containment tree entries	The METRIC is derived from the containment tree entries defined in ./pm:Relation/@Entries. If Kind is DCE, ./pm:Relation/pm:Code MAY be set to classify the form of derivation.
Oth	Other	Relation is specified by other means, e.g., ./pm:Relation/pm:Code or extension element.