categories & grades of qualification:
special grade of general construction contracting for building works (allowed to undertake business requiring qualification for general construction contracting & general engineering contracting & project management of building works in various grade )
1st grade of general construction contracting for road works
1st grade of professional contracting for road subgrade works
2nd grade of professional contracting for airport runway works
issued by ministry of housing and urban & rural development of the people's republic of china