at LPPT, LPCS, LPAR, LPMT (Portugal)
Lisbon Approach is the responsable unit for Approach to the 4 aerodrmes mentioned above.
When a Visual Approach clearance is given, the altitude will only be mentioned if there is a need for a altitude restriction, otherwise the Visual Approach clearance 'allows' the descent to final ...
Due to the proximity of Left Downwind RWY 03 for LPPT (Lisboa)and the VFR routes for traffic inbound/outbound LPCS (Cascais), normally the Visual Approach Clearance for RWY 03 LPPt is
"Cleared for Visual Approach Rwy 03, maintain xxxx feet until turning base"
"Clearde for Visual Approach Rwy 03, maintain xxxx feet until further advised"