It is most unlikely to be anti-f, as this specificity will not react with either R1R1 or R2R2 red cells (I presume that you are using both antibody screening cells and antibody identification panel cells that have these phenotypes represented).
Anti-f reacts with red cells where the c and e antigens are the result of an RHCE*ce haplotype where, for want of a better way of putting it, the c and e antigens are the result of the RHc and RHe genes being in the cis position - NOTE THAT THIS TERMINOLOGY IS (KNOWINGLY) WRONG!
Like all Rh antibodies, anti-f reacts most strongly with its cognate antigen on red cells that have been treated with a proteolytic enzyme (such as papain or ficin), but will very often react with untreated red cells by IAT.
Prince Domson reacted to Malcolm Needs in Non specific antibodyIt is most unlikely to be anti-f, as this specificity will not react with either R1R1 or R2R2 red cells (I presume that you are using both antibody screening cells and antibody identification panel cells that have these phenotypes represented).