THE classification of Candida albicans into two serological groups on the basis of agglutination tests was first reported by Hasenclever and Mitchell1, and both in the original and subsequent papers2–4 these authors and their colleagues referred to group A and group B strains. The findings were confirmed by me5,6 using a double-diffusion method, and, for the sake of conformity, similarly using the word ‘group’ with reference to the serological division within the species. Nevertheless, it must be apparent that this terminology is not consistent with that relating to the serological classification of other microbiological species such as Pneumococcus and Haemophilus influenzae, where the word ‘type’ is employed, and that confusion may arise if the word ‘group’ is used to describe not only an antigen (group antigen) which is common to more than one species of a particular genus, but also the serological division within a species.