A Label is the technology-specific value to distinguish a single data stream embedded in a larger data stream.

A Label may have the following UML properties:
* label type: a URI to refer to a technology-specific labelset
* value is one value taken from the labelset
Technology extensions of NML may define additional attributes.


The following XML syntax is proposed:

  <nml:Port id="....">
    <nml:label labeltype="http://schemas.ogf.org/nml/ethernet/2013/10/vlan">42</nml:label>
  </nml:Port>

  <nml:Port id="....">
    <nml:label labeltype="http://schemas.ogf.org/nml/wdm/2013/10/frequency">193.10~0.05</nml:label>
  </nml:Port>

(where the exact attributename: "labeltype", "type" or "encoding" is still open for debate in artf6577)


The following RDF syntax is proposed:

  @prefix  nml: <http://schemas.ogf.org/nml/base/2012/10#>; .
  @prefix  nmleth: <http://schemas.ogf.org/nml/ethernet/2012/10#>; .
  ex:myport         a                     nml:Port            .
  ex:myport         nmleth:vlan           "42"                .
  nmleth:vlan       rdfs:isSubPropertyOf  nml:Label           .

  @prefix  nml: <http://schemas.ogf.org/nml/base/2013/10#>; .
  @prefix  nmlwdm: <http://schemas.ogf.org/nml/wdm/2013/10#>; .
  ex:myport         a                     nml:Port            .
  ex:myport         nmlwdm:frequency      "193.10~0.05"       .
  nmlwdm:frequency  rdfs:isSubPropertyOf  nml:Label           .