Cooperative applications are expected to become commonplace in the future. We are concerned here with a special case of cooperation called "indirect cooperation". The idea of the paper is that a Concurrency Control approach better fits to indirect cooperation than a Concurrent Programming one. In other words, it does exist syntactic correctness criteria which defines a large sphere of security in which application programmers are released from the burden of interaction explicit programming. This paper arguments this point of view and describes such a criterion: the COO-Serializability. It applies for a class of applications which cooperate indirectly.