Looking through fairly recently posted serials I noticed one, or maybe two that aren't, really. Not to pick on any one author, but collections of jokes or poems, even hundreds of them, don't make a serial.
Insert joke about Oakmeal and Acorn Flakes as breakfast serials. Mighty Oaks from little Acorns grow.
Serial stories are stories, with characters that continue through different adventures and often locations. Poetry and Jokes don't have plot or continuing characters or any particular order in which they should be read. Possibly there could be a new category that is not serials and not stories. Non-Fiction?
I doubt it is worth while to establish a new category for continuing work that has different heroes, different plots, endings for the particular joke or poem rather than for the series as a whole. Its kind of like Series or Universe in which each individual day's post fits. Depending on how much work it is for Management (I can't spell Lazeez) perhaps future collections could be set up as individual stories and combined as a Universe? Or not, nothing is impossible for the person who doesn't have to do it. When I see serials with well over a hundred chapters I wonder if I start it, will I live long enough to read it all.