+NULL is returned if the sequence is empty.
+The caller should free the returned structures using
+.BR ber_bvecfree ().
+.TP
+.B W
+Sequence of octet strings with lengths.
+A BerVarray * should be supplied, which upon
+return points to a dynamically allocated array of
+struct berval's
+containing the octet strings and their lengths. The array is terminated
+by a struct berval with a NULL bv_val string pointer.
+NULL is returned if the sequence is empty.
+The caller should free the returned structures using
+.BR ber_bvarray_free ().
+.TP
+.B M
+Sequence of octet strings with lengths. This is a generalized form
+of the previous three formats.
+A void ** (ptr) should be supplied, followed by a ber_len_t * (len)
+and a ber_len_t (off).
+Upon return (ptr) will point to a dynamically allocated array
+whose elements are all of size (*len). A struct berval will be filled
+starting at offset (off) in each element. The strings in each struct
+berval reside in memory assigned to the BerElement and must not be
+freed by the caller. The array is terminated by a struct berval
+with a NULL bv_val string pointer. NULL is returned if the sequence
+is empty. The number of elements in the array is also stored
+in (*len) on return. The caller should free the returned array using
+.BR ber_memfree ().