Clogyrnach

Don't know who wrote the following, but I have a fondness for a form description written in that actual form. In fact maybe we should make a challenge of it! Some would be easy, eg an essay about an essay. Others such as a haiku about a haiku could be pretty challenging.

A quantitative Welsh verse form,
The clog-ir-nach defines the norm:
Three couplets that rhyme,
Syllables count time,
Rhymes should climb
And conform.

Yours is better poetry by far of course!