I'm glad to see that the desire to come up with stable definitions and labels for difficult-to-define-and-label things exists not only within the science fiction community, where the desire for taxonomy seems sometimes pathologic, but also within the world at large. Exhibit A: The Queen's English Society is demanding that poems be defined as things with rhyme and meter (or, rather, metre).
Those of us who have survived interminable discussions of what, exactly, makes something science fiction or fantasy can probably help our friends at the Queen's English Society. In fact, we can let them know that the desire for definition does not end with one term. Oh no. One of the great laws of the universe is: Taxonomy breeds taxonomy. Once we have one label or category, we need many. And then the many need many of their own.
For instance, the Queen's English Society will need to determine whether everything defined as "poetry" is (for instance) immersive poetry or submersive poetry, and then they will need to define whether immersive poetry can be subversive when it is not submersive, and if submersive poetry is inherently subversive or if its subversivity is flexible. Then, of course, they will have to figure out if it is hard immersive poetry or soft immersive poetry, and how such a hard/soft binary interacts with the hard/soft binary of submersive poetry, which is a different sort of hard/soft binary because if it's hard/soft and immersive then it tends to sink in polders, while if it is hard/soft and submersive, it can float in polders. That then opens up the new category of Things That Float in Polders, but we're going to have to wait for a panel discussion at whatever convention is happening next weekend to know if poems that are submersive truly belong in the secondary (or is it primary?) category of Things That Float in Polders, or if the submersive subversive poems actually stand at the edge of the polder and interrogate it. Which makes them into submersive subversive interrogators (SSIs), and some people claim that SSIs are actually mystery stories, not poems. Even if they rhyme. But have no fear -- I'm sure the upcoming anthology of The New Submersive Poetry will clear everything up... (Alas, having been down this route before, I know some reviewers will claim that the book only includes a few truly submersive poems, and those few are not subversively submersive, which makes their submersivity merely an artifact of nostalgia rather than a storm against a barricade, but this is okay because it leaves room for the next anthology: The New Storming & Subversive Submersive Poetry, which will be a really cool book, I'm sure, because it will have a blog. Actually, strike that -- it won't even have a book, just a blog.)
If our friends at the Queen's English Society get tired of defining and subdefining poetry (perish the thought!), they can always argue about the origins of poetry and the first poem. In fact, they should claim one poem to be The First Poem -- perhaps Percy Shelley's "Queen Mab: A Philosophical Poem" will do. It's even got the word "poem" in the title, so it must be the first one. Once they have identified a First Poem, the real fun will begin, because it will allow all poem-like objects before it to be categorized as proto-poems, and the possibilities for what can (and can't!) be defined as proto-poems are practically endless. This will allow at least a century of argument, and between this and the argument about defining poetry much fun can be had by many generations of ... people who like to argue about such things! Wheeee!
The real question, though, is what is a pipe?