The shadorma is a poem written as a sestet with a 3/3/5/3/7/5 syllable structure. It is supposedly an old Spanish form, though I’ve yet to see any hard evidence of its origins. Nor has anyone else, judging from the sources available. It’s more likely to be a modern response to the haiku’s popularity.
Nonce forms aren’t so much a category of a poem as a term for one-time use forms, though it’s not uncommon for a nonce form to take on a life of its own after its inception. These forms are often made just as an experiment or a sort of self-invented challenge by an individual writer, who may never use them again.
List poems (or catalog poems) are poems that incorporate a list directly into the fabric of the poem, usually as a framing tool. A list poem can be based on a list of actions, experiences, items, people, etc. The whole poem can be a list or there can be one prominent list featured in the body of the poem.