Currently need to use a params element with the code target=

{search parameter referencing the resource type}

this structure to represent a "reverse" reference:

see example here:

http://build.fhir.org/graphdefinition.html#examples

This seems like common pattern especially for defining a message bundle. see this example: http://build.fhir.org/ig/HL7/davinci-alerts/branches/master/Bundle-message-admit-01.html

So I propose making this a whole lot less opaque by:

1) adding a 'reverseLInk' element 0..*

components ; type, profile, path, min, max, target, link, reverseLink

example:

<target>

<type value="Patient"/>

<profile value="http://hl7.org/fhir/us/core/StructureDefinition/us-core-patient"/>

<reverseLink>

<type value="Coverage"/>

<profile value="http://hl7.org/fhir/us/davinci-hrex/StructureDefinition/hrex-coverage"/>

<reversePath value="Coverage.beneficiary"/>

<min value="0"/>

<max value="1"/>

</reverseLink>

</target>...