Found:

Binary Branching Constraint

MORPHOLOGY: a constraint on concatenative word formation which says that in the process of word formation only two morphemes can be concatenated at the same time. Hence, the compound a,i,c either has the structure [[[a] [b]] [c]], or the structure [[a] [[b] [c]]], but not the ternary structure [[a] [b] [c]]. Circumfixes are problematic with respect to this constraint.

SYNTAX: Constraint proposed in Kayne (1984) which rules out syntactic structures in which a phrase contains more than two immediate constituents (i.e. no node in a tree structure may have more than two branches).

LIT.	Spencer, A. (1991)