To make things a little less comlicated than they appear, "Unified Han characters" as encoded by Unicode put many of the variants m,entioned in this article under one umbrella (codepoint).
However, ou still have to know the subtle differences as they may be of relevance for morphoanalytic input methods such as the 4-Corner Index - a project (i.e., the editor window and its "logistics") that I hope we can discuss in a near future.