In my lab we follow the ANZSBT guidelines as shown below http://www.anzsbt.org.au/publications/documents/PLP_Guidelines_Mar07.pdf 2.1.3.5 The specificity of an antibody [including each individual antibody in multiple antibody mixtures] can normally be assigned when it is reactive with at least two reagent red cells carrying the corresponding antigen and non-reactive with two reagent red cells lacking the antigen. 2.1.3.6 The presence of anti-Jka, anti-Jkb, anti-S, anti-s, anti-Fya and anti-Fyb should be excluded using red cells with double-dose expression of the corresponding antigens.
We often find Anti-D (presumed passive) when doing elutions for ABO incompatibility in Rh neg mums with Rh pos babes.