XML Schema Complete Reference, The

E.2. Markup

A marked-up character string includes some characters that are markup and some that are data. One job of a parser is to separate the two.

markup:

characters added into a string of data characters to identify and provide information about the data. It can be divided into metadata and punctuation.

data character:

1. A character in an XML document that an XML parser recognizes as data (rather than markup).

2. A character information item in the children of an element information item.

3. Such a character information item or a character in the value of an attribute.

metadata string:

1. A character string recognized as markup but retained in the abstract data structure because it provides information about the abstract structure. (Example: ...