Categorially obscure words of relations, sometimes accompanied by semantic obscurity too, characteristically occur between the connected constituents regardless of the specific word-order setting of a language. This chapter investigates two kinds of such connectors, the conjunctions and the linkers. It is argued that the functional void of UG responsible for the grammatical behaviors of connectors is that UG cannot project any lexical item without a categorial specification. If a lexical item does not acquire a category for some independent reason, its consequential lack of syntactic representation leads to unique grammatical behavior dependent on the specific semantic relation it encodes. In the case of conjunctions, the symmetric nature of ‘and’ and ‘or’, triggering linear iconicity while restricted by the isomorphic implementation of the USM, results in representing conjuncts on parallel planes of which one is the “default” due to computational cost. It is this simultaneous symmetry–asymmetry enforced by the UG-iconicity interface that explains a large set of apparently self-contradictory traits of coordination. Linkers from Mandarin Chinese, Chamorro and Cantonese are analyzed in a similar manner.