Hi Dimitri, I'm not clear on what your object is in using ordinal. You are correct nominal provides the same result. If you're simply asking how to apply an ordinal custom property in the Information Map, it is applied the same way you would apply any of the other custom properties when defining the Information Map for Marketing Automation. In data item custom properties, you need to 1) CLASSIFY the data item as "category"
2) Under CUSTOM select "Level" custom property and "Value" custom property then enter value of "ordinal" (best practice: nominal,interval ID) per the attached sample I provided any previous response.
Prior to 6.X CI Studio tool had the capability to display a graph of how your data items are represented in the select. This feature is no longer available (to my knowledge) therefore the use of ordinal has no real value. The use of nominal provides the same result.
If you have a specific issue you're attempting to address by using ordinal, I'd strongly recommend submitting a track with SAS Technial Support on use of the "SAS Information Map for Marketing Automation" so that you get the proper guidance to resolution and what is currently supported.
Happy Marketing!