The <ruleBase> element groups a set of rules specified in <rule> and <compositeRule> elements. The specification of rules in NCL 3.0 was done in a separate module, because they are useful for defining either alternative components or alternative descriptors.
| Element | Attributes | Content | Parent |
|---|---|---|---|
| <ruleBase> | id | (<importBase> | <compositeRule> | <rule>)+ | <head> |
| Name | Value | Description |
|---|---|---|
| id | It may receive any string value that begins with a letter or an underscore and that only contains letters, digits, “.”, and “_”. | The id attribute uniquely identifies the element within a document. |