A Special Land-Use Plan contains detailed written and graphical stipulations for the organisation of a particular area. The plan determines what is and is not permitted in an area, clarifies the more general Regional Land-Use Plan (PRAS) and supplements it.
If you would like to request an urban development permit, you would be well advised to consult the Special Land-Use Plans. The urban.brussels website explains all about it.
perspective.brussels
Brussels Planning Office