Lipogram
A lipogram is a kind of writing with constraints consisting of writing full paragraphs or books in which a particular symbol, such as that fifth symbol in talks in which it is most common, is missing. In other words, an author must submit to an awful handicap; only consonants and A, I, O, and U is comprising what is ordinarily a quorum of six fours and two.
This is a trivial task for uncommon symbols such as Z, W, or X, but it calls for much thought if you must avoid a common symbol. In idioms of that South British lingo familiar to Milton (not Scottish, nor Irish, nor Cymric, but that of Gringos, most Canadians, Australians also, and in addition that of austral islands not too far away from Oz), omission of that symbol which follows D, with F following on in its own turn, is most difficult; tough, you might say, and all would concur. Alas, for lack of application, lipogrammatists can slip up and with what upshot? Inclusion of that symbol you had sought to avoid. Oh my, my, such a pity. A shambolic lipogram! Sham! So that you do not miss my point: all of this stuff and rubbish was a Q-lipogram. But now it isn't! What is still missing is that symbol twixt I and K!
Examples of lipograms include the above two paragraphs, Ernest Vincent Wright's Gadsby (1939), and Georges Perec's novel La Disparition, all of which are missing the letter E, which is most common in both French and English. The word comes from Greek elipe gramma, meaning "he left out a letter".
Perec is one of a group of French authors who adopted a variety of constraints in their work. Together they form Oulipo.