Question about portability guidelines

[Paul Smith]

Looking at the portability guidelines[1] there is some confusion; early
on it says:

> Currently we assume at least a freestanding C89 compiler

But then later in that same section I see things like:

> The GNU coding standards allow one departure from strict C99

and:

> Hence Gnulib code should avoid using constructs (e.g., undeclared
> functions return int) that do not conform to C99.

etc.  Are these references to C99 typos, and they should be C89 instead?

Also, I see this:

> Gnulib code can assume that standard internal types like size_t are no
> wider than long.

Is that right?  On a 64bit system compiling with Microsoft Visual C,
long is only a 32bit integer.  Is it saying that gnulib is specifically
not intended to work with MS Visual C?


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[1] 
https://www.gnu.org/software/gnulib/manual/html_node/Portability-guidelines.html