In a scripture passage, often there is a little letter at the beginning of the passage, indicating that there is a cross reference.
For example: In John 15:4, there is a "d" at the beginning of the passage. If you click on the "d", the cross references show up as "John 17:23; Eph. 3:17; [Col. 1:23]".
What do the brackets "[" around Col. 1:23 mean?