Under-punctuation

Mr. Kirkup was probably ill-advised to print the long poems. Over-paragraphing, under-punctuation, and short lines, make them appear wispier than they really are, and some good imagery and observation is swamped by the personal and dreamy fantasy.

Source: wiktionary

Under-punctuation (which is fashionable to-day) throws a great deal of the burden of interpretation on the reader, and sometimes leaves him with obscurities and ambiguities. Over-punctuation has the same effect as unnatural variations of the voice and exaggerated gestures in speaking.

Source: wiktionary

The short answer would be that both bear the customary stigmata of avant-garde prose: typographical oddity, under-punctuation, a liberal sprinkling of the four-letter words.

Source: wiktionary

There has been the war against split infinitives, over-capitalization, under-punctuation, spelling errors, and misplaced modifiers.

Source: wiktionary