 ROT13 provides an opportunity for letter games . Some words will , when transformed with ROT13 , produce another word . Examples of 7 @-@ letter pairs in the English language are <unk> and nowhere , and Chechen and purpura . Other examples of words like these are shown in the table . The pair gnat and tang is an interesting example which are both ROT13 reciprocals and ( taken together ) a palindrome . 
