PAUSE Definition of Pre-Alpha, Alpha, Beta and Released Software

I ask this question in specific relation to the "Development Stage"
choice on the PAUSE Register Namespace form, though I guess it is
really far more generic than that:

Is there a formal or accepted definition of the various stages of
software development within the Perl community, and if so I would be
grateful if someone could point me in the right direction to pick up a
bit more knowledge?

I have Googled on the subject and definitions seem to be vague and
vary quite significantly, particularly between the pre-release/pre-
stable stages: pre-alpha/alpha/beta. I have put together a brief
description below based on my research so far and look forward to
being corrected!

Idea - just an idea, no code yet.
Pre-Alpha - first stab at code, proof-of-concept, likely to be very
buggy, interface could change dramatically, entirely untested.
Alpha - starting to take shape but still likely to be buggy and
largely untested, interface settling down but still open to
significant change.
Beta - nearly there, largely tested and working, one or two known
bugs, interface unlikely to change dramatically but no guarantees.
Released - comprehensively tested, no _known_ bugs, interface is
formalised and future development/bug fixes should take this into
account.

On Aug 14, 9:35 am, Dan Otterburn <dan.otterb...@gmail.com> wrote:

> Is there a formal or accepted definition of the various stages of
> software development within the Perl community, [...]?

[snip]
anno4...@radom.zrz.tu-berlin.de wrote in comp.lang.perl.misc:

> There is no such definition.  It is left to the individual module
> author to assign one of the development stages to published code.
> Most authors seem to pass over the stages below "released".
[/snip]

This question was answered by Anno in a separate post on
comp.lang.perl.misc and with whose permission I copy the answer to
here for the sake of completeness.

(I was unsure as to how to "quote" someone else's answer from a
different thread, so apologise if I have broken protocol.)