 Backwards words can be indicated by words like "climbing", "retreating", or "ascending" (depending on whether it is an across clue or a down clue) or by directional indicators such as "going North" (meaning upwards) or "West" (right-to-left); letters can be replaced or removed with indicators such as "nothing rather than excellence" (meaning replace E in a word with O); the letter "I" can be indicated by "me" or "one;" the letter "O" can be indicated by "nought", "nothing", "zero", or "a ring" (since it visually resembles one); the letter "X" might be clued as "a cross", or "ten" (as in the Roman numeral), or "an illiterate's signature", or "sounds like your old flame" (homophone for "ex").