Halliday & Matthiessen (1999: 198):
The paradigmatic strategy [of taxonomising], that of inventing new names, typically construes sets of things which are systemically related but not in a relationship of a strict taxonomy. This resource is typically associated with feature networks: that is, networks made up of systems of features, such that each lexical item (as the name of a thing) realises a certain combination of these features selected from different systems within the network — a particular clustering of systemic variables. … This resource, the construal of systematically related lexico-semantic sets, illustrates well the principle of “lexis as most delicate grammar”.