I suspect the adjudicator as to whether a word is common (Alan, I presume?) has a background in chemistry and/or medicine, or at least a strong academic focus in one or both of those fields. My suspicion is fuelled by the pattern I have discerned of classifying as common words which are chemical elements (e.g. lutetium), chemical compounds (e.g. adenine, which used to be common), or technical medical terms (e.g. prolapsed and recta, the latter which used to be common). I can't remember other specific words, but recall multiple instances that a word classified as common was a technical medical term or technical chemical term.

So, is my suspicion close to correct?

This morning the temperature is in the single digits and dry -- perfect for my favourite breakfast: rolled oats, sultanas, and dark treacle.

What are some favourite breakfasts of others here, especially once the heat is past?

I have no doubt that it is impossible for anyone to create a universally-agreed-upon list of common words distinct from rare words for the puzzles. I also realise that anyone judging whether a word qualifies as common will be influenced by personal vocabulary and instances. For instance, I find it rather odd that miso does not qualify as a common word -- but then I enjoy Japanese cuisine.

So, though I find it strange that moonrise is classified as a rare word whilst orison is deemed a common word, I'm sure there is a reasonable explanation. I just can't figure out what it might be! 

A word found in the Authorised Version of the Bible: criest was not accepted. Could we add it, please?

Even though TheFreeDictionary.com includes the word, the word revocate was not allowed. I suggest it be added to the list of permitted words.

Is anyone else having difficulty accessing the puzzle? I've repeatedly tried to load it without success.

airbus a common word? I'd have thought it needed to be capitalised.

I never heard of this. Is this something Aussies drink?