Fragmentary writing is basically whatever an author decides is fragmentary. Only the originator of the expression can know about such things as completeness, whether the start and finish are actually a start or finish or whether there are exclusions. Such things cannot be measured against “standards”, norms or taught mechanics of writing or decided upon by industry or academia appointed grandees.
And of course strictly speaking with the confusionist notion of perpetual writing everything becomes fragmentary although in this case of fragmentary writing theory we are looking at a broader case than just pure confusionist analysis and analysing within more traditional examples where such things completed novels and poems, for example, are considered as discreet pieces of completed art as opposed to just fragments that flow in no planned way through the course of a life and have no real end or start and certainly have much missing which would be pure confusionist analysis. And maybe in this a difference between pure confusionist art and episodic confusionist art can be seen with episodic confusionist art tending more to an at least semi-completed episode, if not piece, in what flows from the author.