What do the "D" codes on region 2 DVDs mean

Some non-U.S. discs from Warner, MGM, and Disney are marked with a distribution zone number. "D1" identifies a UK-only release. These often have English-only soundtracks with BBFC censoring. "D2" and "D3" identify European DVDs that are not sold in the UK and Ireland. These often contain uncut or less cut versions of films. "D4" identifies DVDs that are distributed throughout all of Europe (region 2) and Australia/New Zealand (region 4).