It is my opinion, in general, that posting diagrams without explanations, without context or source, is not very helpful in many, perhaps even most, cases. For example, the TCI library is full of diagrams taken out of context without any explanation. People seem to think that a diagram is the ultimate answer to some yet unknown question.
Many telephones come in a multitude of configurations, wired for various service requirements, and the circuits may be even evolve slightly over time, with changed components or component values. Many times a diagram taken from a catalog or technical reference shows only one configuration, and modifications are explained in prose and tables.
When posting a diagram, I think it should be accompanied by a description of equipment, application, service, time frame, source and whatever else someone might need to properly use the diagram. When I post diagrams, I try to summarize the equipment features, some history, and a general frame of context, such as related equipment, earlier, or later types.
When I encounter a diagram that has nothing with it, I most often simply discard it—well, it goes into a big digital bucket when it sits and waits—when I cannot determine its provenance, or even authenticity. The TCI library, for example, is full of such examples. Elsewhere, one can also find compendia of diagrams without references, and it can be hard to link them to an actual piece of equipment, unless one find the exact diagram in another phone. For example, I have spent enormous times in unraveling a compendium of Kellogg diagrams, and still have not accounted for even the majority of them. One would think it would have been trivial to the originators to write a few sentences about the history of each of those documents. Without that it becomes a waste of time for everyone, one cannot use the diagram for historical studies, unless one finds the same diagram again on a telephone.
