Hi everyone, I recently came upon this in a tourist guide: "Making a toast when drinking alcohol is de rigour." I tried looking up 'de rigour' in various internet dictionaries, but was unable to find an explicit and complete definition. I take it that 'de rigour' is a neologism and has not yet been fully granted a carte blanche. Also, 'de rigour' to me functions as a substitution of 'must' as noun, or something obligatory. Please, tell me if I am right and whether 'de rigour' can operate as a standard phrase in standard texts, say the media. Thank you.