the pedals are completely parallel to each other ("parallel"), or whether the pedals are closer together at the far end than at the end closest to the organ console ("radiating"). Specifications vary by country, organ builder, era, and individual tastes. Exact design specifications for pedalboards are published in Great Britain by the RCO, in the United States by the AGO (which requires a design similar to the RCO's), and in Germany by the BDO (which allows both 30- and 32-note pedalboards, of both concave/radiating and concave/parallel varieties). Pedal division In an organ with more than one keyboard, the stops and the ranks that the stops control are separated into different divisions, in which the ranks of pipes are grouped together so that they make a "focused" or coherent sound. The pedal division, which is played from the pedal keyboard, usually includes more stops of 16′ pitch. The sound of the pedal division is generally voiced so that the pedal division complements the sound of the great division. Common 16′ stops found in the pedal division include the 16′ Bourdon, the 16′ Principal, and the 16′ Trombone. Eight foot stops include the 8′ Open Diapason. Pedal divisions may also include higher-register stops, such as the 4′ Choral Bass or various mixtures. When pedal parts are performed, a 16′ stop is usually paired with an 8′ one to provide more definition. For pedal parts that need accentuation, such as the Cantus Firmus melody in a 17th-century organ piece, many organs have a nasal-sounding reed stop in the pedal division, or a 4′ Principal designated on the stop knob as "Choralbass". A few pedalboards have a pedal divide system that lets the organist split the pedalboard at its midpoint. With this system, an organist can play a melody with the right foot and a bass part with the left. The divided pedal is a type of coupler. It allows the sounds played on the pedals to be split, so the lower octave (principally that of the left foot) plays stops from the pedal division while the upper half (played by the right foot), plays stops from one of the manual divisions. The choice of manual is at the discretion of the performer, as is the 'split point' of the system. The system can be found on the organs of Gloucester Cathedral, having been added by Nicholson & Co (Worcester) Ltd/David Briggs and Truro