In « Parsing arguments and building values » (c-api/arg.html), it should
be made clear that "*" typecodes are recommended over the "#" typecodes,
which are inherently unsafe.

(more generally, the page is totally unreadable, a solution might be to
group the typecodes by family: numbers, strings/buffers, objects; also,
there are so many choices that it's confusing which ones should be
preferred)

This only really applies in 2.x, actually. In 3.x, "#" should be
discouraged for another reason: it is overly strict and will only accept
pure read-only objects (which don't have a bf_releasebuffer method);
even bytearrays will be rejected.