![[ebnf]](figures/rev_ebnf.png)
| Content Model | |||
| |||
| Attributes | Common attributes | ||
|
Name |
Type |
Default | |
| linkend | IDREF | Required | |
This element is only available if you are using the EBNF Module.
A Constraint is a cross-reference to a description of a constraint that cannot be expressed in the grammar (generally logical rather than syntactic constraints).