Hudson (1970) should be credited for identifying and defining the Malayic Dayak subgroup. Previous scholars were not aware of this subgroup and classified the Malayic Dayak languages either with the Malay dialects spoken by Muslims on the Borneo coast or with the Land Dayak languages. In this way they classified Iban as a Malay dialect, and Salako as a Land Dayak dialect with strong Malay influence. Kendayan Dayak was seemingly also considered as a strongly Malayicized variety of Land Dayak (cf. Cense and Uhlenbeck 1958). Hudson, however, calls Iban, Kendayan, Salako and other closely-related Dayak languages ‘Malayic Dayak’, and he classifies them together with Malay and other Malay-like languages^[10] into the ‘Malayic’ linguistic group. His term ‘Malayic Dayak’ is meant to distinguish Malayic languages spoken by non-Muslims in Borneo from other Malayic languages. It is therefore not a linguistic term sensu stricto, but the term is relevant in Bornean linguistics insofar as it distinguishes autochthonous Malayic languages from Malayic languages which are the result of later migrations of (Muslim) Malays into Borneo (e.g. Banjarese, Sarawak Malay, Brunei Malay and other Malay varieties spoken by Muslims).

Hudson’s classification of Iban, Salako, Kendayan and related languages into a single subgroup distinct from Land Dayak is very important, as it emphasizes the fact that these languages are relatives of Malay which have undergone a separate development, and not hybrid forms of Malay with a strong non-Malay substratum or adstratum. In other words, these languages are highly relevant for the history of Malay and for the reconstruction of Proto-Malayic. For instance, Salako and Kendayan retained the causative prefix maka- and the subjunctive suffix -à? (Kendayan -a?). maka- and -à?/-a? reflect Proto-Malayo Polynesian (henceforth PMP) *maka-, a causative prefix, and PMP *-a, a subjunctive marker respectively. Both were lost in other Malayic languages.

Examples:

Salako rehetn ‘light’ vs maka-rehetn ‘make lighter (a punishment)’

Kendayan lalu ‘past, further’, molot ‘mouth’ vs makalalu molot ‘keep one’s promise, act according to what one has said’

Salako mare? ‘to give’ vs mare-a? ‘in order to give, so as to give’

Salako nabàkŋ ‘chop off’ vs nabakŋ-à? ‘in order to chop off, intending to chop off’

Compare also the following Malayic Dayak words (from Iban and Salako) which were retained from PMP, and which were usually lost in other Malayic languages:

Iban ui, Salako ui? ‘rattan’ < PMP *qu ə y (Malay rotan);

Iban, Salako asu? ‘dog’ < PMP *asu (Malay anji ŋ);

Iban tama?, Salako tamà? ‘go inside’ < PMP *tama? (Malay masuk);

Salako tau, talu ‘three’ < PMP *t ə lu (Malay, Iban tiga);

Iban mua, Salako muhà ‘face’ < PMP *muha (Malay muka);

Iban, Salako gaway ‘ceremony’ < PMP *gaway (Malay upacara);

Iban sa?, Salako asà? ‘one’ < PMP *ə sa? (Malay suatu);

Iban sida?, Salako ne? idà? ‘they’ < PMP *siDa (Malay m əreka);

Salako (sacral language) u$it^[11] ‘yellow’ < PMP *ku ɲ ij ‘curcuma’ (Malay, Iban kuni ŋ ‘yellow’);

Iban buuk, Salako bu?uk ‘hair of head’ < PMP *buh(u ə )k (Malay rambut).

An indication of the historical relevance of Malayic Dayak is the fact that many grammatical and lexical elements retained from Proto-Malayic in the seventh century Old Malay inscriptions in South Sumatra are still found in Salako and Kendayan (the ‘West Malayic Dayak’ dialects), whereas other Malayic languages have lost them. This is the case with some lexical items and also with the above affixes maka- and (Salako) -à?/ (Kendayan) -a?, which occur in Old Malay as maka- and -a (with apparently the same meanings). The passive marker in most Malayic languages is di-. This marker apparently did not exist in Old Malay (which used ni- instead), whereas in Kendayan and Salako it has not developed into a passive marker, but rather into an agent marker which is prefixed to the verb in case the agent is not expressed.

Another important aspect about Malayic Dayak languages is that until recently they kept out of the main stream of Sanskrit, Arabic, Javanese, Persian and European influences which so heavily affected the lexicons of other Malayic languages.

Hudson’s classification also pays attention to the fact that the Malayic Dayak languages are indigenous, whereas other Malayic languages in Borneo were introduced from Sumatra and/or Malaysia. This is important for the search of the original Malayic homeland. Three areas have been considered as a homeland: Sumatra, the Malay peninsula and Western Borneo. Kern (1889) was in favour of a homeland in the peninsular Malay area, and he rejected the possibility of a Bornean homeland. But his arguments do not hold (Adelaar 1988). The historical and linguistic evidence suggests that the Malayic settlements in the Malay peninsula are of more recent date than those in Sumatra or in Borneo (Bellwood 1993). In view of the geographical spread (in the interior), the variety (which in some cases cannot be explained as due to contact-induced change) and the sometimes conservative character of Malayic Dayak languages, some linguists tend to favour Borneo as the homeland of the Malayic languages (cf. Blust 1988; Adelaar 1988, 1992).