| Attribute | Description | Type |
| define | A comma-separated list of preprocessor macros to define. Use nested define elements to define macro values. | StringArrayBuilder |
| description | Sets a description of the current data type. | String |
| id | Sets an id that can be used to reference this element. | String |
| if | Sets the property name for the 'if' condition. The define will be ignored unless the property is defined. The value of the property is insignificant, but values that would imply misinterpretation ("false", "no") will throw an exception when evaluated. | String |
| refid | Specifies that this element should behave as if the content of the element with the matching id attribute was inserted at this location. If specified, no other attributes or child content should be specified, other than "description". | Reference |
| undefine | A comma-separated list of preprocessor macros to undefine. | StringArrayBuilder |
| unless | Set the property name for the 'unless' condition. If named property is set, the define will be ignored. The value of the property is insignificant, but values that would imply misinterpretation ("false", "no") of the behavior will throw an exception when evaluated. | String |