Carroll was tricksy and he loved codes. He was never much into cryptography - although many people believe that his work was full of hidden messages and I have seen whole books written with the aim of "revealing" what is apparently "hidden" in his works. Usually the writer sees almost entirely the meanings they want to see. (This is a risk that all commentators take of course).

Carroll devised a game called Doublets in which you transform one word into another of the same length, changing one word at a time, with the minimum number of "steps". The link is here.

I wondered if it was possible to change CRYPTIC to DELUDED but stalled instantly on CRYPTIC.