Until the last decade of the 16th century the emphasis is on "divisions", also known as "diminutions", "passaggi" (in Italian), "gorgia" ("throat", first used as a term for vocal ornamentation by Nicola Vicentino in 1555), or "glosas" (by Ortiz, in both Spanish and Italian) – a way to decorate a simple cadence or interval with extra shorter notes. These start as simple passing notes, progress to step-wise additions and in the most complicated cases are rapid passages of equal valued notes – virtuosic flourishes. There are rules for designing them, to make sure that the original structure of the music is left intact. Towards the end of this period the divisions detailed in the treatises contain more dotted and other uneven rhythms and leaps of more than one step at a time.