this is the current state in lion:

Usage of the signification pattern

Sign is realized correctly by Designation (abstract)
 - contains property "representation" of type Signifier (complex data type from the pattern)
 - contains relation "denotes" of type Concept (realizing Signified)
Signified is realized correctly by Concept 
 - Nothing to be contained as Signified is empty

Designation is super class of Code
 - overrides property "representation" by type CodeValue
 - overrides relation "denotes" by type Category (ERROR - not realizing Signified)
Designation is super class of Datum
 - overrides property "representation" by type DatumValue

Concept has no sub class