It seems a group closely related to Punan almost by default, described as nomad. For example, the Tatau were nomads (see Diman Jarap 1961), and so too were the Sitieng (Tuton Kaboy 1971).
Such was, and to a certain extent still is, the misconception people’s have of Punan in Sarawak. This is partly no fault of Punan. In Borneo, the term had been used as an exonym for an entirely different groups of people — the nomads scattered in central and southwest of Borneo. In Kalimantan Indonesia it is the policy of government to name all former nomads as “Punan” (see Shanti Tambiah 2007).
But in Sarawak, Punan is also the name of an agriculturalist group. British anthropologist, Dr Edmund R. Leach, proposed to call “Punan Bah” — partly to avoid them being confused for Penan that Kayan and Kenyah in Sarawak often labeled Punan! Hence, in the literature, they are generally known as “Punan Bah” — actually a misleading exonym. It is with the Punan in Sarawak or Punan Bah with whom the Sitieng historically are related.