Is it "double existence," or "similarity semantics" of data? What does it mean, when/if, we point at a "data-object" that is "shared" (even if read-only), in a message-based distributed/networked system?
For example, in Fig.2 of copycat83, that data-"object" (D3), sent by "C3" and received/read by two different entities (both "C5" and "C6") cannot be a concrete "data-object" (as a token-attribute is). They must be two different messages, if this is a message-based system.
A guess is "similarity semantics." That begs the claim, first. No discussions about that, in copycat82/83, if that were meant, at all. In any case, now that I mentioned a possibility of representation, let's go on a bit.
In such a case, it must be a "meta data," a "documentation of similarity." But such a "documentation" is, possibly, prone to the versions-problem (and possibly, to other problems, too.) i.e: Other than such, at-immediately-after-a-fork, and especially if any loop(s) exist(s), the two entities that are reading the "meta data" writtem/sent by the same entity, could be referring to different versions.
i.e: Once it is not a unique-entity but a "meta data," the reader would require the definition, before reading/interpreting a net/model. There are no such discussions in copycat82/83. Therefore, in a claimed-to-be "message-based" system, this is a shared-memory representation. The clash exists, observably, because copycat82/83 is plagiarizing from both E-nets and others/VD78. E-nets have token-attributes, that we perfectly know where they belong to. VD78 refers to memory-cells (Keller/Karp, etc.) in data-graph. When the internals of an E-net token is repainted, with a lot of parallel paths to it, one per each attribute (data), this is copycat82/83. This is only one of the awkward results, at the seams between various papers.