Ruf or Ruff: How To spell?
The word Ruf is misspelled against Ruff, a noun meaning "A collar on a shaft ot other piece to prevent endwise motion. See Illust. of Collar."
Ruff has double 'ff' in the end mispronounced as 'f'Remember double 'FF' appears in the end of this word which should not be misspelled with single 'F'
Wrong Spelling:  ru-f  Correct Spelling:  ru-ff 
Check more misspelled words of Ruff to spell it correct.