Currently boolean fields default to none/empty, but once a value has been chosen it is not possible to remove the value anymore.
Use case: We sell food and household products and have a field called "Vegetarian". If one by accident set that field to true/yes on a household product it is not possible to remove and that field will be used for filtering, showed on product pages etc.
Any update on this? We are currently using text option fields (with values TRUE and FALSE) to get around this which is really annoying.
From what I have heard it used to be possible in previous versions of Litium.