I wrote:

This does not imply that a scheme can't be used which simply represents the passwords as-is, nor that slapd or slap tools have any business stripping away such a {scheme} prefix. In particular not when that's the only way to represent cleartext passwords starting with "{letters}".

...OTOH perhaps it's too late to change {cleartext} now if it has an established useful meaning. Could introduce a new scheme called {plaintext} or {raw} instead for this purpose.