Dear all, It appears that at least two packages, AnnotationDbi and rols, define the Ontology generic with the same signature setGeneric("Ontology", function(object) standardGeneric("Ontology")) Could it be moved to BiocGenerics, please? Best wishes, Laurent -- Laurent Gatto | @lgatt0 http://cpu.sysbiol.cam.ac.uk/ http://lgatto.github.io/