The Support Selection Rule (SSR) helps you place appropriate supports in a model by providing a sorted list of recommended supports in the Type box. You must check the Rule box on the ribbon to enable this command.
The sort order in the drop down list is based on a property of the support, IJUAHgrRulePriority ::Rule Priority. The RulePriority is an integer number that can be set by the project administrator to set the sort order of supports. The lower in the number in RulePriority, the higher in the list the support will appear. If you do not specify a RulePriority, or if there is more than one support with the same RulePriority, then the list of assemblies is sorted alphabetically based on PartDescription.