This About - Releases shows 1.8.3 as latest, but my Arduino IDE install seems to be 1.8.6. so is this really the latest?

[brewmanz]

If this repo is 1.8.3 and not the latest (which might be 1.8.6), maybe stick a note on this 'front page' mentioning where the latest can be found

[per1234]

The inconsistent creation of releases by the project's maintainers has already been reported at #95. Please close this duplicate issue to keep the issue tracker tidy @brewmanz.

maybe stick a note on this 'front page'

The solution is for the maintainers to simply take a few seconds to click the button to create GitHub releases from the tags.

where the latest can be found

Here:

https://github.com/arduino/ArduinoCore-megaavr/tags

It also seems you might be confused as the latest version is 1.8.8, not 1.8.6. If you would like to discuss the subject further, just post over on Arduino Forum. We'll be happy to explain anything you might be unclear on over there:

https://forum.arduino.cc/c/community/general-discussion/17

[brewmanz]

A) closing as a duplicate, to keep the issues tracker 'tidy'. I wonder when they'll decide to keep the release/tag consistency 'tidy'.
B) I'm not confused by the 1.8.3/1.8.6 inconsistency; the 'is this really the latest' in the header related to the '1.8.3'. On re-reading my header wording, I realise that it's ambiguous; maybe I need to be 'tidy' in my wording in future.