The documentation for Py_TPFLAGS_DEFAULT mentions Py_TPFLAGS_HAVE_STACKLESS_EXTENSION and Py_TPFLAGS_HAVE_VERSION_TAG, but neither of them is documented.  They aren't mentioned in the 2.6 documentation (presumably because they were introduced in 3.x?).

http://docs.python.org/dev/py3k/c-api/typeobj.html?highlight=py_tpflags_have_gc#Py_TPFLAGS_DEFAULT

I don't think these flags need documenting or even deserve mentioning. Py_TPFLAGS_HAVE_STACKLESS_EXTENSION seems to be two bits reserved for use by Stackless, while Py_TPFLAGS_HAVE_VERSION_TAG should be considered by extension authors an internal implementation detail (in normal circumstances, it won't impact how they have to write their code or the semantics of their extension types).

I think if they are mentioned, they should be documented.  Removing mention of them would be fine with me.

Looking at this again, I think the description of Py_TPFLAGS_DEFAULT is no longer accurate.  It reads: "This is a bitmask of all the bits that pertain to the existence of certain fields in the type object and its extension structures. Currently, it includes the following bits: Py_TPFLAGS_HAVE_STACKLESS_EXTENSION, Py_TPFLAGS_HAVE_VERSION_TAG."

But neither of those flags pertain to the existence of certain fields, do they?

Perhaps it should simply read: "This bitmask should be set by all types to define certain bits used internally by Python."

@Daniel could you supply a patch for this?