Halliday & Matthiessen (2014: 390):
The element following the Head is also a modifying element; we can distinguish the two positions by using the terms Premodifier and Postmodifier. The distinction is not a functional one, but depends on the rank of the modifying term; compare a weatherboard shack by the roadside with a roadside shack made out of weather board. These two are not synonymous, but the difference lies in the information structure: the item located at Postmodifier has the greater potential as news. But the Postmodifier does not itself enter into the logical structure, because it is not construed as a word complex.