In the UK what does "MSC" stand for in food labelling?

MSC stands for "Marine Stewardship Council". The blue MSC label is an independent sustainability mark which indicates that seafood has been sourced using methods which minimise impacts upon the marine environment and fish stocks. The MSC's standards comply with UN guidelines on eco-labelling. For over 20 years the Council has worked with scientists, fisheries, seafood producers and brands to develop standards and promote sustainable fishing. The MSC is the only wild-capture fisheries certification and Eco labelling programme that meets best practice requirements set by both the United Nations Food and Agriculture Organization (UNFAO) and ISEAL, the global membership association for sustainability standards. In March 2017, the MSC became the first global seafood certification program to be recognised for rigour and credibility by the Global Sustainable Seafood Initiative (GSSI).

Complementing MSC work, the RSPCA Freedom Food label and the Global Aquaculture Alliance label apply only to sustainability farmed fish. "Seafish" is a Non-Departmental Public Body (NDPB) set up by the Fisheries Act 1981 to improve efficiency and raise standards across the seafood industry.