Zess is the name of a character in the Initial Teaching Alphabet

Initial Teaching Alphabet

The Initial Teaching Alphabet was developed by Sir James Pitman in the early 1960s...

, a series of about 40 minuscule letters specified by Sir James Pitman

James Pitman

Sir James Pitman, KBE was a British businessman, civil servant, publisher, politician and spelling reformer.Sir James was vitally concerned with the teaching of children to write the English language...

, grandson of an inventor of shorthand

Shorthand

Shorthand is an abbreviated symbolic writing method that increases speed or brevity of writing as compared to a normal method of writing a language. The process of writing in shorthand is called stenography, from the Greek stenos and graphē or graphie...

, to assist children in their learning to read English. Its form is easy to describe: it is a backward z.

The use of the zess is to replace the letter s where it is pronounced /z/ in English; most obviously in the word is. Those plural

Plural

In linguistics, plurality or [a] plural is a concept of quantity representing a value of more-than-one. Typically applied to nouns, a plural word or marker is used to distinguish a value other than the default quantity of a noun, which is typically one...

s of nouns or third-person present forms of verbs in which the letter s is voiced are spelled with a zess (dogs for both uses); those in which it is unvoiced are still spelled with an s (barks for both uses). The ITA also has a z for use in other places.

The zess is specified only as minuscule in form. For an equivalent of a capital letter, it is made boldface.