In ENVO's alignment with the Basic Formal Ontology, this class is being considered as a subclass of a proposed BFO class "system". The relation "environed_by" is also under development. Roughly, a system which includes a material entity (at least partially) within its site and causally influences that entity may be considered to environ it. Following the completion of this alignment, this class' definition and the definitions of its subclasses will be revised.