Speakers generally prefer semantically related content to be expressed nearby in the string, yet certain constructions allow semantic long-distance dependencies (LDDs). Why do LDDs exist and how and why are they constrained? Here, new evidence is brought to bear in support of the following claim: LDDs, which make a constituent prominent, may not target backgrounded content, nor can they asymmetrically target an aspect of content construed as symmetric.  Studies demonstrate that LDDs from single conjuncts are rated more acceptable to the extent that (i) the targeted conjunct expresses more prominent content or (ii) the entire conjunction is construed as describing a single complex event rather than two events. Processing factors, namely familiarity and intransitivity of the first conjunct, are found to influence the acceptability of LDDs in addition to the discourse-semantic factors.