 ROT47 is a derivative of ROT13 which , in addition to scrambling the basic letters , also treats numbers and common symbols . Instead of using the sequence A – Z as the alphabet , ROT47 uses a larger set of characters from the common character encoding known as ASCII . Specifically , the 7 @-@ bit printable characters , excluding space , from decimal 33 ' ! ' through 126 ' ~ ' , 94 in total , taken in the order of the numerical values of their ASCII codes , are rotated by 47 positions , without special consideration of case . For example , the character A is mapped to p , while a is mapped to 2 . The use of a larger alphabet produces a more thorough obfuscation than that of ROT13 ; for example , a telephone number such as + 1 @-@ 415 @-@ 839 @-@ 6885 is not obvious at first sight from the scrambled result Z` \ c`d \ gbh \ eggd . On the other hand , because ROT47 introduces numbers and symbols into the mix without discrimination , it is more immediately obvious that the text has been enciphered . 
