47.1. An alteration of the diagnostic characters or of the circumscription of a taxon without the exclusion of the type does not warrant a change of authorship of the name of the taxon.
Ex. 1. When the original material of Arabis beckwithii S. Watson (in Proc. Amer. Acad. Arts 22: 467. 1887) is attributed to two different species, as by Munz (in Bull. S. Calif. Acad. Sci. 31: 62. 1932), the species not including the lectotype must bear a different name (A. shockleyi Munz) but the other species is still named A. beckwithii S. Watson.
Ex. 2. Myosotis as revised by Brown differs from the genus as originally circumscribed by Linnaeus, but the generic name remains Myosotis L. because the type of the name is still included in the genus (it may be cited as Myosotis L. emend. R. Br.: see Rec. 47A).
Ex. 3. The variously defined species that includes the types of Centaurea jacea L. (Sp. Pl.: 914. 1753), C. amara L. (Sp. Pl., ed. 2: 1292. 1763), and a variable number of other species names is still called C. jacea L. (or C. jacea L. emend. Coss. & Germ., C. jacea L. emend. Vis., or C. jacea L. emend. Godr., as the case may be: see Rec. 47A).
47A.1. When an alteration as mentioned in Art. 47.1 has been considerable, the nature of the change may be indicated by adding such words, abbreviated where suitable, as “emendavit” (emend.) followed by the name of the author responsible for the change, “mutatis characteribus” (mut. char.), “pro parte” (p. p.), “excluso genere” or “exclusis generibus” (excl. gen.), “exclusa specie” or “exclusis speciebus” (excl. sp.), “exclusa varietate” or “exclusis varietatibus” (excl. var.), “sensu amplo” (s. ampl.), “sensu lato” (s. l.), “sensu stricto” (s. str.), etc.
Ex. 1. Phyllanthus L. emend. Müll. Arg.; Globularia cordifolia L. excl. var. (emend. Lam.).