Syntax Notation

The syntax of each XML element is specified as follows:

The content specification can be "EMPTY", a data format name, or an element group. EMPTY means that this element has no body (nested content). A data format name means that the body can be any text string matching the named format. An element group means that the named elements can be directly nested within this element.

An element group consists of one or more element names (or element groups) enclosed in parentheses, and separated with commas or vertical bars. Commas indicate that the elements (or element groups) must occur in the XML sequentially in the order listed in the group. Vertical bars indicate that exactly one of the elements (or element groups) must occur. An element or element group can be followed by a ? (meaning optional), a * (meaning zero or more occurrences), or a + (meaning one or more occurrences).

Attributes are listed in tabular form, one attribute per row, including the attribute's name, its data format, its optionality, and possibly some semantic details. All attributes are required unless the optionality column contains "(optional)". The ODM foundation schema implements the specification using XML Schema.