Ms 7826 Ver 1.0 Manual
Also, consider that "MS" might not be an acronym at all. Could it be a part of a longer model number, like MS-7826-1 or similar? The version number might indicate that the manual has been updated, but the user is referring to the original version.
Before using the manual, confirm that it matches your exact equipment or software version. Look for: ms 7826 ver 1.0 manual