When homosexuality was illegal in the UK, John Maynard Keynes kept a coded diary of his activities. The code’s simplicity, which uses ‘C’, ‘W’ and ‘A’ to denote events, hasn’t stopped the discussion about its meaning fierce.
C = child, W = woman and A = adult makes a lot of sense to me.
The people at More Intelligent Life (the website of the Economist spin-off) have many other ideas…