# As the relation data also a derivation of MetaClass RELATIONDATA can be used. For example to store more data on the relationship.
{{HintAttention|Relations have to be unqiue, so you can not create two relations with the same name!}}
{{Hint|The system creates an additional (but only internally used) MetaClass containing the relational data. This MetaClass will be created in the same namespace as its template. If the Namespace of the template ends with "Template", this part is replaced with "Data". E.g: Namespace of the template: "'''Custom.Relation.Template'''", leads to a new Namespace '''"Custom.Relation.Data'''"}}