Provided are LR and MS Recordings. LR is decoded from the MS and has the approximate stereo width as an XY recording. On the MS tracks the mid mic is on the left and the side mic on the right. The LR can be encoded back into MS or if panned center cancels out the side mics to just play the mid mic. Alternately in the provided MS file, the right side channel can be dropped so you can use the mono center.
The 2 files are mastered the same. Occasionally the levels vary on the MS track as these are the levels set to keep the tracks phase coherent. All tracks are edited to be M&E friendly, and monitored through a phase scope to again, keep the tracks phase coherent.