[. … .]) ¶Collating symbols can be represented inside lists. You form a collating symbol by putting a collating element between an open-collating-symbol operator and a close-collating-symbol operator. ‘[.’ represents the open-collating-symbol operator and ‘.]’ represents the close-collating-symbol operator. For example, if ‘ll’ is a collating element, then ‘[[.ll.]]’ would match ‘ll’.