Tag 'ref = O'

• 7: ref
• 4: railway
• 3: name
• 2: wheelchair
• 2: roof:shape
• 2: building:levels
• 2: description
• 2: entrance_marker:subway
• 2: entrance
• 2: railway:signal:direction
• 2: level
• 2: building:part
• 2: railway:signal:position
• 1: destination
• 1: public_transport
• 1: railway:signal:main
• 1: building
• 1: operator
• 1: railway:signal:distant:height
• 1: railway:signal:traversable
• 1: railway:signal:combined:states
• 1: railway:signal:combined:height
• 1: name:ja
• 1: railway:signal:traversable:type
• 1: check_date:wheelchair
• 1: building:levels:underground
• 1: railway:signal:combined:form
• 1: railway:signal:combined
• 1: railway:signal:combined:function