Folks, Many subscribers to Ontolog Forum, including me, are or have been working or collaborating with various standards organizations -- ISO, OMG, IEEE, etc. And many others have important ideas, requirements, or suggestions for standards of various kinds. But Ontolog Forum is not a standards organization, and any emails that anybody posts to Ontolog Forum will go no further than the Ontolog website. Anybody is free to use those suggestions, but they will have no official standing or certification of any kind. For theoretical issues about representations of any kind, first-order logic is fundamental. Anything that is specified in FOL is guaranteed to be absolutely precise to the finest detail. Furthermore, anything and everything implemented in or on any digital device of any kind can be specified in FOL. Therefore, I strongly recommend FOL as the foundation for specifying all computable representations of any kind. There are, however, some kinds of information that may require extensions to modal or higher order logics for certain kinds of features. Issues that go beyond FOL have been specified in logics, such as Common Logic and the IKL extensions to CL. But in every case, logic is fundamental. It's impossible to have a precise specification of anything that cannot be translated to and from FOL or to some formally defined logic that includes FOL as a proper subset. I know many of the Ontolog subscribers with whom I had been discussing these and related issues in meetings and email lists since I first began to work with standards organizations in the early 1990s. I'm sure that they can add much more info about these matters. Fundamental issue: It's pointless to waste large amounts of human time and computer cycles on discussion of standards without considering whether and how any of this discussion could be developed into international standards by some official standards organization(s). And FOL and/or some extensions to FOL should be the ultimate foundation for any of those standards. John PS: It's OK to use subsets of FOL for some purposes, since any subset can be translated to FOL. But FOL itself has a very clean and simple translation to and from natural languages with just seven common words: and, or, not, if-then, some, every. It is the ideal common representation for anything computable. Any specification in FOL can be accompanied by an automatically generated translation to any desired natural language.