MIL-STD-31000B - Non-geometric data stored in 3D model files.

Action Engineering - A dimension or metadata of a particular feature that is not visible in the model and is accessed via model query.

MBE Maturity Index - Non-visible information contained in, or related to, a model.

Model-Based Characteristics (MBC) - An item of non-visible information contained in, or related to, a model that is available upon interrogation of the model.