 The words : ( colon ) , POSTPONE , ' ( tick ) are examples of parsing words that take their arguments from the user input device instead of the data stack . Another example is the word ( ( paren ) which reads and ignores the following words up to and including the next right parenthesis and is used to place comments in a colon definition . Similarly , the word \ ( backslash ) is used for comments that continue to the end of the current line . To be parsed correctly , ( ( paren ) and \ ( backslash ) must be separated by whitespace from the following comment text . 
