The "where" attribute is an outdated NH feature - it's the predecessor of the filter features, and although it's not deprecated as such, documentation does generally recommend you use filters instead of the where-attribute -
Is there any way to add custom attributes to the generated mapping files? If so, I could define the filters by hand, and apply them to the model using a custom property... Again, documentation for the template API is sparse...Hibernate3 has the ability to pre-define filter criteria and attach those filters at both a class level and a collection level. A filter criteria allows you to define a restriction clause similar to the existing "where" attribute available on the class and various collection elements...