Customizing the metamodel : Definitions: Creating and modifying : Adding and changing definitions
  
Adding and changing definitions
A definition block starts with the keyword Definition followed by a string (the argument) that is the name of the definition type. If the string has an embedded space, it must be enclosed in quotes (that is, both “definition type” and definition_type are acceptable).
Syntax
To add more properties for a definition, use:
DEFINITION definition_type { PROPERTY-1 <property_name> { <property_value> } PROPERTY-2 <property_name> { <property_value> } PROPERTY-3 <property_name> { <property_value> } }