Comment by dhosek

In the Perec instance, it's what was called by the Oulipo group (of which he was a part), a Lipogram. Perec wrote a follow-up text in which the only vowel used was e. A Canadian author wrote a suite of five novellas each restricting themselves to a single vowel. In his case, he went through a dictionary by hand and created vocabulary lists for each novella.

I've read the English translation of La disparition and I'd note that (a) the act of translating a Lipogram is kind of its own special challenge (which might be also why the Spanish version chose to omit a instead of e—without e, a wide class of plurals and all third-person forms of to be are lost, although a rules out most feminine nouns) and (2) the writer/translator ends up building a vocabulary of standard circumlocution to avoid the forbidden letter, e.g., “this/that man” in place of “he.”