<relation>

<relation> (relationship) describes any kind of relationship or linkage amongst a specified group of participants. 15.2.2 The Participant Description
Modulenamesdates — 13 Names, Dates, People, and Places
Attributesatt.global (@xml:id, @n, @xml:lang, @rend, @rendition, @xml:base, @xml:space) (att.global.linking (@corresp, @synch, @sameAs, @copyOf, @next, @prev, @exclude, @select)) (att.global.analytic (@ana)) (att.global.facs (@facs)) att.datable (att.datable.w3c (@period, @when, @notBefore, @notAfter, @from, @to)) (att.datable.iso (@when-iso, @notBefore-iso, @notAfter-iso, @from-iso, @to-iso)) att.editLike (@evidence, @source) (att.dimensions (@unit, @quantity, @extent, @precision, @scope) (att.ranging (@atLeast, @atMost, @min, @max)) ) (att.responsibility (@cert, @resp)) att.naming (@role, @nymRef) (att.canonical (@key, @ref))
typecategorizes the relationship in some respect, e.g. as social, personal or other.
Status Optional
Datatype 

<rng:ref name="data.enumerated"/>
data.enumerated
Suggested values include:
social
relationship concerned with social roles
personal
relationship concerned with personal roles, e.g. kinship, marriage, etc. [Default]
other
other kinds of relationship
namesupplies a name for the kind of relationship of which this is an instance.
Status Required
Datatype 

<rng:ref name="data.enumerated"/>
data.enumerated
Values an open list of application-dependent keywords
activeidentifies the ‘active’ participants in a non-mutual relationship, or all the participants in a mutual one.
Status Optional
Datatype 1–∞ occurrences of 

<rng:ref name="data.pointer"/>
data.pointer
separated by whitespace
Values a list of identifier values for participant or participant groups
mutualsupplies a list of participants amongst all of whom the relationship holds equally.
Status Mandatory when applicable
Datatype 1–∞ occurrences of 

<rng:ref name="data.pointer"/>
data.pointer
separated by whitespace
Values a list of identifier values for participant or participant groups
passiveidentifies the ‘passive’ participants in a non-mutual relationship.
Status Optional
Datatype 1–∞ occurrences of 

<rng:ref name="data.pointer"/>
data.pointer
separated by whitespace
Values a list of identifier values for participant or participant groups
Used by
Contained by
namesdates: listEvent listNym listOrg listPerson listPlace relationGrp
May contain
core: desc
Declaration

<rng:element name="relation">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.datable.w3c.attributes"/>
 <rng:ref name="att.datable.iso.attributes"/>
 <rng:ref name="att.editLike.attributes"/>
 <rng:ref name="att.dimensions.attributes"/>
 <rng:ref name="att.ranging.attributes"/>
 <rng:ref name="att.responsibility.attributes"/>
 <rng:ref name="att.naming.attributes"/>
 <rng:ref name="att.canonical.attributes"/>
 <rng:optional>
  <rng:attribute name="type" a:defaultValue="personal">
   <rng:choice>
    <rng:value>social</rng:value>
    <rng:value>personal</rng:value>
    <rng:value>other</rng:value>
    <rng:data type="Name"/>
   </rng:choice>
  </rng:attribute>
 </rng:optional>
 <rng:attribute name="name">
  <rng:ref name="data.enumerated"/>
 </rng:attribute>
 <rng:choice>
  <rng:optional>
   <rng:attribute name="active">
    <rng:list>
     <rng:ref name="data.pointer"/>
     <rng:zeroOrMore>
      <rng:ref name="data.pointer"/>
     </rng:zeroOrMore>
    </rng:list>
   </rng:attribute>
  </rng:optional>
  <rng:optional>
   <rng:attribute name="mutual">
    <rng:list>
     <rng:ref name="data.pointer"/>
     <rng:zeroOrMore>
      <rng:ref name="data.pointer"/>
     </rng:zeroOrMore>
    </rng:list>
   </rng:attribute>
  </rng:optional>
 </rng:choice>
 <rng:optional>
  <rng:attribute name="passive">
   <rng:list>
    <rng:ref name="data.pointer"/>
    <rng:zeroOrMore>
     <rng:ref name="data.pointer"/>
    </rng:zeroOrMore>
   </rng:list>
  </rng:attribute>
 </rng:optional>
 <rng:optional>
  <rng:ref name="desc"/>
 </rng:optional>
</rng:element>
element relation
{
   att.global.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.datable.w3c.attributes,
   att.datable.iso.attributes,
   att.editLike.attributes,
   att.dimensions.attributes,
   att.ranging.attributes,
   att.responsibility.attributes,
   att.naming.attributes,
   att.canonical.attributes,
   attribute type { "social" | "personal" | "other" | xsd:Name }?,
   attribute name { data.enumerated },
   (
      attribute active { list { data.pointer, data.pointer* } }?
    | attribute mutual { list { data.pointer, data.pointer* } }?
   ),
   attribute passive { list { data.pointer, data.pointer* } }?,
   desc?
}
Schematron

<s:report test="@active and @mutual">Only one of the attributes
'active' and 'mutual' may be supplied</s:report>
Schematron

<s:report test="@passive and not(@active)">the attribute 'passive'
may be supplied only if the attribute 'active' is
supplied</s:report>
Example
<relation
  type="social"
  name="supervisor"
  active="#p1"
  passive="#p2 #p3 #p4"/>

This indicates that the person with identifier p1 is supervisor of persons p2, p3, and p4.

Example
<relation type="personal" name="friends" mutual="#p2 #p3 #p4"/>

This indicates that p2, p3, and p4 are all friends.

Note
Only one of the attributes active and mutual may be supplied; the attribute passive may be supplied only if the attribute active is supplied. Not all of these constraints can be enforced in all schema languages.