It is very much to Stanley's credit that he recognized the special kinship of "positive conditions" to syllable structure at a time when syllable structure had scarcely begun to be explored in generative phonology. As a matter of fact, "positive conditions" are to my knowledge "only" found in connection with restrictions involving syllable structure (or more precisely prosodic structure including feet as well as syllables).
- Kiparsky (2004), a pag.155