Hi :) I try to use a MARelationDescription with an object that fetch its description automatically from instances... and I have a problem... To illustrate, let's take the Magritte tutorial example with 2 model classes MAPersonModel and MAAdressModel. In MAPersonModel we have an inst var homeAdress with the corresponding description on the class side: MAPersonModel class>>descriptionHomeAddress ^ (MAToOneRelationDescription auto: 'homeAddress' label: 'Home Address' priority: 40) componentClass: MAInternalEditorComponent; classes: (Array with: MAAddressModel); yourself. and that is enough because MAAdressModel has its descriptions defined (class side). But if descriptions were accessed from instance of MAAdressModel like: MAAdressModel>>descriptionGenerated ^MAPriorityDescription new add: (MAStringDescription auto: 'street' label: 'Street' priority: 10); add: (MAStringDescription auto: 'place' label: 'Place' priority: 30); ... yourself. Then I was thinking it was possible to create the previous description in the following way (say there are no more desciption in the class side of MAAdressModel): MAPersonModel class>>descriptionHomeAddress ^ (MAToOneRelationDescription auto: 'homeAddress' label: 'Home Address' priority: 40) ***reference: MAAdessModel new descriptionGenerated;*** componentClass: MAInternalEditorComponent; classes: (Array with: MAAddressModel); *no more description in the class side of MAAddressModel* yourself. I know in this exemple, the interest of doing that is not obvious but this is because in my case, I have specific description for instances (one part is general whereas the other is created with values affected to the object). Is it possible to do that way ? what is the correct use of #reference: for a MARelationDescription ? choosing a kind of container ? Is there a built-in way to use different descriptions (filtered for instance) than the one accessed from the classe that are in ToOne or ToMany relation ? Thank you Cédrick