This property identifies E57 Material employed in an E11 Modification. The E57 Material used during the E11 Modification does not necessarily become incorporated into the E24 Physical Man-Made Thing that forms the subject of the E11 Modification.

This property identifies the instances of E57 Materials of which an instance of E18 Physical Thing is composed. All physical things consist of physical materials. P45 consists of (is incorporated in) allows the different Materials to be recorded. P45 consists of (is incorporated in) refers here to observed Material as opposed to the consumed raw material. A Material, such as a theoretical alloy, may not have any physical instances

This property identifies an E57 Material foreseeen to be used by an E29 Design or Procedure. E29 Designs and procedures commonly foresee the use of particular E57 Materials. The fabrication of adobe bricks, for example, requires straw, clay and water. This property enables this to be documented. This property is not intended for the documentation of E57 Materials that were used on a particular occasion when an instance of E29 Design or Procedure was executed.