f.

1) abbreviation for forma or form (i.e. a neutral term for a single individual, phenon, or taxon; a group; or an infrasubspecific group, or in the past, a subspecies (not recommended usage)). According to the International Code of Zoological Nomenclature the use of the term "form" before 1961 is not to be interpreted as an express statement of either subspecific or infrasubspecific rank and after 1960 it is to be regarded as of infrasubspecific rank)

an abbreviation for figura, meaning figure or illustration