Rhymed, end-to-end palindromic (RETEP) verse, as I conceive of it, has only one obligatory rule which is not self-explanatory, and that is that to qualify as RETEP, a verse must possess a least two mutually exclusive pairs of rhyming lines.
"Six-Line RETEP Verse,"
Word Ways: Vol. 52
, Article 7.
Available at: https://digitalcommons.butler.edu/wordways/vol52/iss2/7