Problems with linking to archive.org Wayback machine.
1. They have limited bandwidth. 
2. Production linking, as opposed to research like Jack did to find the 'missing' page, stretches the meaning of 'fair use'.

Potential problems with external docs.
1. Don't directly fit our needs.
2. Cannot be edited by us.
3. Can disappear.

The Mozilla doc is obviously framed in terms of problems with Firefox, which is quite a different beast from Python.  In my opinion, it is too long, somehow seems repetitious, and is a bit hard to read.  I find it hard to imagine that many Python beginners will read the whole thing.

Some of the advice, such as "Version: select the earliest Version with what the problem can be reproduced:" is wrong for our workflow.

I would like our doc to recommend that real beginners, with less than a couple of months of experience, and anyone else with doubts, post first on python-list, asking "Is this a bug, and if not, please explain.

Version: select the earliest Version with what the problem can be reproduced:

A doc that we might link to, perhaps as a supplement to anything we write, is https://stackoverflow.com/help/minimal-reproducible-example.