(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. Examples illustrating marking of various kinds in possessive noun phrases are (1)-(4) below. In possessive phrases, the possessed noun is head and the possessor is dependent."