There are tombstones in a number of cemeteries around the Madison AL area that are marked with the logo as you describe. I have a photo of one at the Inman Cemetery on Redstone Arsenal in Madison Co., AL that is quite clear and the date of death is 2/2/1930. The triangle has R C F in the corners and in the center is 09. This person belonged to the Plain View Circle #9. Other stones have different numbers and different names so there were a number or circles in this vicinity. I have checked in many places to try and find the history and objective of this "fraternal" organization. I think that if I can ever find the records it would unlock a good deal of the African American history in this area. Im still searching!