data.pattern

data.pattern (regular expression pattern) define una gama de valores de atributos expresados como una expresión regular.
Módulotei — 1 The TEI Infrastructure
Declaración
data.pattern = token
Nota
A regular expression, often called a pattern, is an expression that describes a set of strings. They are usually used to give a concise description of a set, without having to list all elements. For example, the set containing the three strings Handel, Händel, and Haendel can be described by the pattern H(ä|ae?)ndel (or alternatively, it is said that the pattern H(ä|ae?)ndelmatches each of the three strings)
wikipedia