data.pattern

data.pattern (regular expression pattern) 正規表現を属性値として定義する.
モジュールtei — 1 The TEI Infrastructure
宣言
data.pattern = token
解説
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