XML Schema Complete Reference, The

10.6. The restriction Element

The restriction element provides the functionality to add constraining facets to a simple type. For all simple types except those that represent lists and unions, the simpleType contains a restriction. In the case of a list or a union, a simple type derived from the list or union must add the restrictions.

10.6.1. Attributes of a restriction Element

A restriction has two attributes: base and id Table 10.3 provides a brief summary of the base and id attributes. The subsequent two sections discuss these attributes in detail.

Table 10.3. Attribute Summary for a restriction Element

Attribute	Description
base	The value of the base attribute identifies the base simple type, which is often a built-in datatype, of the ...