Keep/Drop dice

Drops the specified number of lowest/highest dice.

Syntax  
dYdZ XdYdZ Drops the lowest Z dice from the result of XdY. Alias for XdYdlZ. May be used with ns and !.
dYdlZ XdYdlZ Drops the lowest Z dice from the result of XdY. May be used with ns and !.
dYdhZ XdYdhZ Drops the highest Z dice from the result of XdY. May be used with ns and !.
dYkZ XdYkZ Keeps the highest Z dice from the result of XdY. Alias for XdYkhZ. May be used with ns and !.
dYkZ XdYkZ Keeps the highest Z dice from the result of XdY. May be used with ns and !.
dYklZ XdYklZ Keeps the lowest Z dice from the result of XdY. May be used with ns and !.
  None of these can be used with Critrange notation.