It is generally expected that "independent implementations" will interoperate. In particular, see RFC 2026, "Internet Standards Process", which includes the following: 2026> Thus, a candidate specification must be implemented and tested for correct operation and interoperability by multiple independent parties and utilized in increasingly demanding environments, before it can be adopted as an Internet Standard. AB> Does this make specifications recommended or required to interop test, the must was not capital? 2026> In general, an Internet Standard is a specification that is stable and well-understood, is technically competent, has multiple, independent, and interoperable implementations with substantial operational experience, enjoys significant public support, and is recognizably useful in some or all parts of the Internet. AB> I was told that independent implementation = independent and different implementation, is that true? AB>Does independent mean, that number of implementors read the specification separately and implemented without contact or dependance? or that the implementation does not have to work with other implementation of same spec? AB> Does independent mean separately or jointly each of the following were implemented; - implemented in different languages but same implementor, - implemented by different implementors and same code langauge, - the number of implementations (with same implementor) were then modified but does not contradict the specification. Please advise, AB