This file points to 4 pairs of files of the form    "?op*"
("?" is a single-character wildcard and "*" is a multiple-character wildcard.)

Crossing File	Backbone Overlay
1op4_A	1op4_A_sse
1opc	1opc_sse
1opd	1opd_sse
1opo_A	1opo_A_sse