Changes made by 90/553/EEC: Commission Decision of 9 November 1990 establishing the identification mark for equidae vaccinated against African horse sickness
EU Decision 1990/553
No changes made by 90/553/EEC: Commission Decision of 9 November 1990 establishing the identification mark for equidae vaccinated against African horse sickness are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.