Constrained writing

Constrained writing is a literary technique in which the writer is bound by some condition that forbids certain things or imposes a pattern.

The most common constrained forms of writing are strict restrictions in vocabulary, e.g. Basic English, E-Prime, defining vocabulary for dictionaries, and other limited vocabularies for teaching English as a Second Language[?] or to children. This is not generally what is meant by 'constrained writing' in the literary sense, which is motivated by more aesthetic concerns. For example:

• a letter (commonly e or o) is outlawed, making a lipogram;
• a poem similar to Poe's "Raven" (called Near a Raven) has been composed in which the lengths of words are the values of the digits in pi;
• palindromes, such as the word "radar", read the same both ways.
• acrostics
• reverse-lipograms[?] (each word must contain a particular letter)
• Ander-Saxon
• anagrams.
• aleatory (where the reader supplies a random input)

• Haiku Japanese poem
• Chinese poetry
• Dui lian[?] Chinese couplet (對聯)

The Oulipo group is a gathering of writers who use such techniques.