In a subordinate compound, one member can be identified by the head and the other member of the compound is its complement.
An example of this kind is the sign meat^CL(5): ‘flat’, which is composed by the sign meat (the head) and by a whole entity classifier.
meat^CL(5): ‘flat’
‘(Meat) steak’ (recreated from Santoro, 2018: 44)
Another kind of syntactic relation inside the compound is the attributive one. In this type of compound, one member is the head while the other one is a modifier, often an adjective. An example of this type of compound is the sign for memory^SASS(flat open 5): ‘rectangular_prism’, meaning ‘hard disk’, where the classifier modifies the sign memory, which acts as the head of the classifier.
memory^SASS(flat open 5): ‘rectangular_prism’
‘Hard disk’ (recreated from Santoro, 2018: 41)