Given the Irish position on Brexit (that continued membership of the EU was a bedrock of the Good Friday process), and suggestions that Mrs Thatcher made certain similar commitments (whether informally or formally but less well-known) to the Japanese in the 1980s are there any other hidden "understandings" - whether written into an obscure sub clause of a treaty or contract, or just heavily implied - that are waiting to pop up in the future ?
In a country which managed to add 3,000 laws to the statue books in 10 years, it would be amazing if there wasn't some ambiguous wording somewhere.