Currently, in LayOut, the label tool is hardcoded to only access the following attribute dictionaries by name:
"dynamic_attributes"
(can be attached to both component instances and definitions, but only group instances)"SU_InstanceSet"
(attached to instances)"SU_DefinitionSet"
(attached to definitions)- Classification dictionaries attached to definitions listed as keys in
"AppliedSchemaTypes"
Previously I had suggested that there be a way that custom extension dictionaries be accessible to the LayOut label tool, but (AFAIK) it has not yet been implemented.
So, for now extensions would need to save LayOut accessible data into one of the dictionaries named above. Since these dictionaries are a shared data space, it is strongly advised that extensions prefix their attributes with their unique extension name.
Example prefix: "Wisext_F&R_"