Ahmedabad is a city where Jainism coexists with Hinduism. Jainism, from a philosophical point of view, at least from the "spirit of the law" perspective, is not very far from Buddhism. It has three principles: Harm minimization (non violence), multiplicity of points of views and non attachment. Some actually believe that Jainism and Buddhism may be two different arms that stemmed from the same original message. So Ahmedabad, in the state of Gujarat, has a substantial Jain population. The problem for the visitor passing through the state, is that the Jain temples look similar, at least from far away, to the Hindu temples. So how can we tell them apart? "It's easy" was I told. Everything is in the flag. The Jain temples have long, rectangular flags, while the Hindu temples have short, triangular ones. In fact, while the fundamental principles of the two religions remain quite different, in the rites, they are commonalities and crossovers. A visit to selected Jain temples offers opportunities to witness practices that are close to the offerings ("Pujas") seen in Hindu temples. Similarly, as I was having lunch with two colleagues, Hindu brahmins, from the state of Gujarat, I was surprised to see them follow the Jain diet that exclude roots vegetables, on the basis of a rationale that was comparable to the one invoked by Jains. It made me think of the sharks and the dolphins, who, despite their major difference in terms of their position in the genetic tree of the animal world, have adapted and evolved in a similar environment to end up looking quite similar (This being meant without any metaphoric innuendo or value judgement with respect to the two religions considered). Of interest, there is an easy way to differentiate sharks from dolphins: Sharks have a vertical tail fin while dolphins have an horizontal one. These animals are probably at the origin of the flag concept that seems so necessary to facilitate identification from a distance.