The key to writing an acrostic is to spell out words using the first letter of each line of poetry. For instance, an acrostic for the word "baby" would have a first line beginning with "B," a second line beginning with "A" and so on. It is possible to write an acrostic forming several words. In this case, each word usually has its own verse and the verses can be separated by a line. If two words are short, they can share the same verse.
The word "acrostic" comes from the Greek words "akros," meaning "at the end," and "stichos," meaning "line." The prophecies of the Erythraean Sibyl were written on leaves and arranged so that the initial letters formed a word. Latin playwrights Ennuis and Plautus also wrote acrostics. Other famous poets known to use acrostics include Edgar Allan Poe and David Mason.
An alphabet poem is a special form of acrostic that is also called an abecdearian acrostic. These poems spell out the alphabet instead of a word and, therefore, begin with A and end with Z. In some cases, they do not spell the entire alphabet but merely a section of it.
Acrostic poems do not have to rhyme, although they sometimes do. This makes them free-form poetry, which allows the writer to have lines as long or as short as he pleases. Some may even have only one word per line. They also tend to be short, although there is no required length.