According to the documentation, UUIDs can be constructed either from a string or a byte array. In my opinion the term "byte array" could lead to misinterpretation since, in my understanding, the constructor expects a sequence of characters representing the HEX digits not a sequence of bytes: indeed, the sequence has 32 elements (32x4=128) and not 16 (16x8=128). Also, when you state that every function is thread-safe, do you mean that several threads can work simultaneously on different instances? I am not sure if this is thread-safety or reentrancy. I know that there isn't an universally accepted definition, but at lest there should be one accepted by all Boost developers. I saw that in the documentation of an older version of Boost.Thread there was a glossary < http://www.boost.org/doc/libs/1_34_0/doc/html/thread.html#thread.glossary> where there is the definition of thread-safe program, but it seems that the glossary was removed by the newer documentation < http://www.boost.org/doc/libs/1_36_0/doc/html/thread.html>. In my opinion there should be, for example in Boost.Thread, a definition of terms such as thread-safe, reentrant (class, function), so that when an author uses them can add a link to the corresponding paragraph in order to avoid misunderstanding. Best regards, Manuel Fiorelli