When we have a model where an entity has some properties collections used for displaying it to the customer and we are not querying our data by these properties at all, it may seem right to map these collections in NHibernate as collections of components. Component in NHibernate is an object without its own identity, being a part of its parent entity. Our collections sounds similiar in terms of lifetime and ownership, but different in terms of relationship - these are one-to-many. In complex scenarios, additional queries became a serious issue. We've decided to try another solution - it's so simple that it can't go wrong.