I would like to ask people who present new libraries to Boost, in whatever stages they are, to please specify in the documentation to the library and/or in messages regarding the library, what level of C++ compliance is needed to use the functionality of that library. This plea is not being directed at any particular current library being mentioned by anyone on the mailing list, but is a general plea regarding developers and their efforts. I realize it is a real pain that C++ as a language, and as it continues to evolve, has a number of popular levels of C++ compliance. This is largely because C++ is offered by a number of different vendors in a number of different supported releases, each particular implementation supporting a number of levels of C++ compliance and sometimes only partially supporting a particular level of C++ compliance. But given this sometimes difficult situation I do not see it as enough for library docs/information to simply say "this library supports some-vendor/some-release" because this is actually fairly meaningless to me when I know that "some-vendor/some-release" supports a number of levels of C++ compliance through some compiler parameter ( often -std=something ). Therefore docs/information of "the library supports "some-implementation" or "the library is compliant with "more than one level of C++ compliance" tells me as much as if some one told me that the moon is yellow. So I am begging, pleading, entreating library authors to be specific about the C++ features or the C++ level of compliance needed to use their library, even if it is just a one-liner that succinctly explains what the end-user needs to know. Furthermore, for any given library could we please have specific information about what will happen if I use the library, or some feature of the library, without the desired minimum level of C++ compliance. While I would assume compile-time compiler errors as the norm another possibility, especially given the excellent support in Boost Config to compiler conformance, are more readable preprocessor errors. Finally a library might offer some level of advanced C++ compliance but fall back to a lower level if possible. Please, please library authors this is important. No end-user or tester of your library wants to spend extended time trying to figure out why some compile fails when the answer turns out simply to be one of inadequate C++ conformance level for a particular compiler implementation being used with a particular level of conformance.