what is the syntax for category reassignment

Eg : A new item is created and this defaults the item category on the item to xyz based on the categoy assignment rule

set up done as below

Name	Catalog assignment
Description	Auto assignment of item to catalog/category based on given attributes.
Return type	Catalog category
Primary If Expression	True
Secondary If Expression	[Item].[Properties].[Size] == "XS" AND [Item].[Properties].[Material] == "Wool"
Return Value	Catalog[KidsWear].Category[Winter]

the Requirement here is that , even if i change the item category to a different category say Summer manually on the item . this should default to Winter

similarly if when i create an item if i set the category to Summer on this item having the properties as per the expression the category should always default to Winter