IEV improvements: Ability to refer a concept relationship to a concept in an external concept system

[ronaldtse]

1. In IEC 60050 series, concepts are grouped together in a single concept system in a database (the Electropedia).

2. In ISO, standards like ISO 3166 are grouped in a database.

In ISO 30042 TBX this is addressed by the attribute conceptPosition inside <descrip>, but they take plaintext.

We should have a defined notation for referencing concepts in concept systems.

[opoudjis]

termrefs are termbase + id; that can be represented as URN

https://tools.ietf.org/html/rfc5141

[opoudjis]

At a conceptual model level, what is there to say? I'm just referring to termref. This is not the place to explode out all the ways people reference termbanks. The serialisation of termref will need to encompass URNs as an alternative.

[opoudjis]

Addressed by adding +ref to RelatedConcept:

class RelatedConcept {
  +type: RelatedConceptType
  +content: <<BasicDocument>> LocalizedString
  +ref: <<StandocDocument>> ReferenceToTermbase[0..1]
}