Writeprint is a term proposed by some forensic linguistics

Forensic linguistics

Forensic linguistics is the application of linguistic knowledge, methods and insights to the forensic context of law, language, crime investigation, trial, and judicial procedure. It is a branch of applied linguistics...

 researchers to denote a set of distinguishing stylometric

Stylometry

Stylometry is the application of the study of linguistic style, usually to written language, but it has successfully been applied to music and to fine-art paintings as well.Stylometry is often used to attribute authorship to anonymous or disputed documents...

 characteristics of a written text (writer invariant

Writer invariant

Writer invariant, also called authorial invariant or author's invariant, is a property of a text which is invariant of its author, that is, it will be similar in all texts of a given author and different in texts of different authors. It can be used to find plagiarism or discover who is real author...

s) such as "vocabulary

Vocabulary

A person's vocabulary is the set of words within a language that are familiar to that person. A vocabulary usually develops with age, and serves as a useful and fundamental tool for communication and acquiring knowledge...

 richness, length of sentence

Sentence (linguistics)

In the field of linguistics, a sentence is an expression in natural language, and often defined to indicate a grammatical unit consisting of one or more words that generally bear minimal syntactic relation to the words that precede or follow it...

, use of function word

Function word

Function words are words that have little lexical meaning or have ambiguous meaning, but instead serve to express grammatical relationships with other words within a sentence, or specify the attitude or mood of the speaker...

s, layout of paragraph

Paragraph

A paragraph is a self-contained unit of a discourse in writing dealing with a particular point or idea. A paragraph consists of one or more sentences. The start of a paragraph is indicated by beginning on a new line. Sometimes the first line is indented...

s, and key words

Keyword (linguistics)

In corpus linguistics a key word is a word which occurs in a text more often than we would expect to occur by chance alone. Key words are calculated by carrying out a statistical test which compares the word frequencies in a text against their expected frequencies derived in a much larger corpus,...

" which allow one to identify its author (if it is written by a single author).

Metaphorically speaking, a writeprint is like a digital fingerprint

Digital fingerprint

Digital fingerprint may refer to:* Message digest - The output of a one-way function when applied to a stream of data.* Device fingerprint - A compact summary of software and hardware settings collected from a remote computing device....

. It is suggested that writeprints could provide forensics

Forensics

Forensic science is the application of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action...

experts with a new tool for identifying criminals in a digital medium.