EXPLANATIONS OF COLUMNS IN THE MAC, SECTIONS II, III AND IV.
a. Column (1) - Group Number. Column 1 lists functional group code numbers, the pur-
pose of which is to identify maintenance significant components, assemblies, subassem-
blies, and modules with the next higher assembly.
b. Column (2) - Component/Assembly. Column 2 contains the item names of components,
assemblies, subassemblies, and modules for which maintenance is authorized.
c. Column (3) - Maintenance Function. Column 3 lists the functions to be performed on the
item listed in column 2. (For detailed explanation of these functions, see paragraph B.2.)
d. Column (4) - Maintenance Level. Column 4 specifies each level of maintenance autho-
rized to perform each function listed in column 3. An "X" indicates the level at which
maintenance will be done. Ammunition maintenance does not require specific time allo-
cations for tactical items. The symbol designations for the various maintenance levels
are as follows:
C - Operator or crew maintenance
O - Unit maintenance
F - Direct support maintenance
H - General support maintenance
D - Depot maintenance