Permanent establishment defined as fixed business presence; dependent agents and service provision can create tax nexus under a treaty. The document defines permanent establishment as a fixed place of business with enumerated examples and provides that supplying services or hired plant and machinery for mineral oil prospecting or extraction creates a permanent establishment. It lists exclusions for purely preparatory or auxiliary activities and prescribes agency rules: dependent agents who habitually conclude contracts, maintain delivery stock, or secure orders create a permanent establishment, whereas independent agents acting in the ordinary course do not, unless they act almost exclusively for the enterprise. Insurance premium collection or risk insurance through non-independent agents also constitutes a permanent establishment.