(By Johanna Nichols and Balthasar Bickel): "Locus is a convenient one-word term for what is also known as head/dependent marking. In any kind of phrase, overt morphosyntactic marking reflecting the syntactic relations within the phrase may be located on the head of the phrase, on a non-head (i.e. on a dependent), on both, or on neither. In clauses, the arguments are dependents and the verb is the head. Examples of the locus types in clauses are (1)-(4). For ease of illustration these examples show the treatment of subjects and objects, in languages that treat both identically. As discussed below, not all languages treat subjects and objects identically, and where they are treated differently we have mapped the treatment of objects (specifically, direct objects (P below)). Not all languages treat pronoun and noun arguments identically, and where they are treated differently we have mapped the treatment of nouns."