"At Documenta X last summer, several media and art practitioners met in a project titled Hybrid Workspace, and later called Deep Europe. Echoing the words of the Bulgarian artist Luchezar Boyadjiev, "Europe is at its deepest where there are a lot of overlapping identities", the German critical writer Inke Arns characterises the notion of Deep Europe as follows: "With the notion of Deep Europe we refer to a new understanding of Europe, which leads away from the horizontal measurement of the size of a territory (thus including East/West etc.), towards something that could be called a vertical mapping, or a vertical measuring of the different cultural layers and identities in Europe."
Makela, Tapio. "In Cyberspace - Tales from Deep Europe", SIKSI magazine, #4, Winter 1997, p.30

In my mind "identity overlap" occurs whenever and wherever two or more people (or communities of people) lay claim on the same "territory" of historical, cultural, social, political, religious, language, etc. experiences and/or practices that each one of them considers to be only his/their own. Here the legitimacy of the claim is usually based not on rational but rather on emotional grounds. The claim is usually paralleled by a lack of information and/or knowledge, and/or respect for the claim of the other. And experience is understood in the broadest possible sense as collective (personal) horizon of remembrance. what's most striking and exciting about "overlapping identities" is the constantly observable demonstration of coincidences of some sort in all such cases.
"Identity overlap" is most obviously expressed in political claims over coinciding geographical territories but to base the metaphor on such examples would be far too simplistic. In the Balkans, for instance, whenever there are claims over territories, geographical or historical, they are usually based on everybody claiming the Golden Age - the time that each country considers to be the high point of its historical past: Turkey from the XVII century Serbia from the XIV century, Bulgaria from the X century, Macedonia from the IV century BC, Greece as well, we all know how far back could the Greeks go. However, such claims are usually covering for other interests and/or sentiments.
When I say "overlapping identities" I have in mind something rather more complex, something that is a potential source of conflict, as well as, understanding. For instance, it occurred to me recently that if I was to use the notion of political correctness in order to lay claim for special treatment at international art shows (or simply - quota based participation), I would have had to legitimize my claims on the very simple and historically proven fact that all Slavic population (Bulgarians specifically, in the harshest way and for the longest time) within the Ottoman Empire was "awarded" the status of slaves. Consequently, I would have had to be given just as much preferential benefits as, let's say, Afro-American, Afro-British or just Afro- artists whose ancestors were slaves for far shorter then the 500 years during which Bulgaria was under Ottoman domination. This argument might have served me especially well for Documenta X had I been smart enough to use it way back in, let's say, 1993 - 1994. But, no, I decided to just be myself - the big, for-all-humans, artist that I think I am. As a result I, like some others, was simply out-casted by Cathrine David on the basis of being an Eastern European artist. And as everybody knows by now, for her Eastern Europe is not nearly as interesting /exotic/ as China, for instance. We, artists from Eastern Europe in general, turned out not to be different/oppressed enough for her concept.

By the way, have you noticed that in the Editorial Text of "Documenta X - the book" the authors (presumably C. David is at least one of them) make a badly disguised attempt to blame the existence and the activities of the Eastern European dissident movement before 1989 for the destruction of the French Left movement? You see, some French leftist intellectuals sided with the Party Line in the Socialist countries while others - with the dissidents. That caused a split in the movement and the Right just walked in "on a white horse". It turns out that according to such an argument and to the twisted minds of this book's editors, all of us in EE should have kept our mouths shut (well, I wasn't really much of a dissident before 1989 anyway ... which didn't help me with Documenta X either only to keep the French Left intact and happy? Well, I have to ask then - whose life are/were we living anyway? Regardless of who is right and who is wrong in the above described argument, I think that it is a pure case of "overlapping identities". Whenever in the last several years I have communicated with Western European artists/curators and/or other intellectuals I have had the constant feeling that we are neither all that different nor all that similar. We will never be the same nor will we ever understand each other to the full possible extend either. At least not for some time to come.
This is so because we just overlap. I have survived the Big Utopia only to face now the Big Reality. They have survived the Big Reality only to keep on facing the Big Utopia. Unresolvable difference but incredibly human "identity overlap".