argument list separator: acts as a comma between arguments in an argument list supplied to a function.
"ce'oi" is the word of choice to separate the arguments in bridi3. Using ce'o there has obvious limitations when the selbri actually calls for a sequence. Obviously, ce'oi has issues too if the selbri can accept an argument list, but this can be circumvented more readily with ke...ke'e brackets than it can with ce'o. Consider ".i lo ka broda cu selbri fi ko'a ce'o ko'e". Without inspecting the type requirements of broda and the respective types of ko'a and ko'e, one cannot determine the meaning of the bridi. Furthermore, if one accepts non-static typing of sumti places, multiple correct answers can be given for a question asking what is the bridi1. This would create ambiguity that is otherwise resolved by "ce'oi". See also ka, du'u, me'au