In many cases, the differences between two stylistic sets of forms (such that members of one set don’t occur with members of the other) affect only limited parts of the descriptive system […].
- Harris (1951), Pag. 10

[…] dialect differences […] in many cases are also restricted to particular parts of the descriptive system, the rest of the system being identical for both dialects.
- Harris (1951), Pag. 10

It may be noted that there are not just two descriptive systems—phonology and morphology—but a rather indefinite number, some of these being phonologic and some morphologic. It is thus possible to extend the descriptive methods for the creation of additional systems having other terms of reference. For example, investigations in stylistics and in culture-language correlations may be carried out by setting up systems parallel to the morphologic ones but based on the distribution of elements (morpheme classes, sentence types, etc.) over stretches longer than one utterance.
- Harris (1951), Pag. 364