http://www.symbolicsound.com/zzz/pub/Learn/KymaOldDocumentation/Kyma4.5Manualbody.pdf
page 139
Like Random, OneOverF generates random numbers between zero and one, but it tends to generate numbers that are close to one another for awhile, then make a large jump to a new number, then generate numbers close to that one for awhile, etc. It gets its name from the shape of the distribution in the frequency domain: 1/f or the inverse of the frequency; in other words, there tend to be large, slow changes and small, fast changes. To hear what this sounds like, play 200 oneOverF. Try changing the value of the seeds to hear a different set of events.