`entity-activity` codelist

List of Main Activity codes allowed for a Contracting Entity

Codes

`airport`	Airport-related activities
`electricity`	Electricity-related activities
`gas-heat`	Production, transport or distribution of gas or heat
`gas-oil`	Extraction of gas or oil
`port`	Port-related activities
`post`	Postal services
`rail`	Railway services
`solid-fuel`	Exploration or extraction of coal or other solid fuels
`urttb`	Urban railway, tramway, trolleybus or bus services
`water`	Water-related activities