One possible explanation for the reference to "John 22"

In a recent post, I noted a problem with an apparent scriptural reference to the book of John chapter 22. The book of John only has 21 chapters according to the modern system of division, and in the Byzantine manuscripts that I have been able to find, there are only 18 or 19 kephalaia.

However, in the section of the RC in question, the number 22 is written with the number 2 followed by the number 20, as though it were the Roman numeral IIXX.  I had thought this meant "two and twenty", but another explanation could be that this is a language where the number 18 is expressed as "two from twenty".

The only language I can think of at the moment where this is done is Latin: duodēvīgintī, but there may be others. Indeed, it turns out the Romans sometimes wrote 18 as IIXX, which lends a little weight to this hypothesis.

For this explanation to work, we would have to assume that the references are to a copy of the New Testament that is divided according to an earlier system like the Byzantine kephalaia.

If so, then this passage may offer us a good crib. I may look into that this evening.