TM 9-2815-250-24&P B-3. EXPLANATION OF COLUMNS IN SECTION II, MAINTENANCE ALLOCATION CHART FOR ENGINE ASSEMBLY, DIESEL, HATZ 2 G 40 (continued). troubleshooting/fault  location  time,  and  quality  assurance/quality  control  time  in  addition  to  the  time  required  to perform   the   specific   tasks   identified   for   the   maintenance   functions   authorized   in   the   MAC.      The   symbol designations for the various maintenance levels are as follows: C ............................................. Operator/Crew O............................................. Unit F ............................................. Direct Support H ............................................. General Support D ............................................. Depot e. (5) Tools and Test Equipment Reference Code.    Column  5  specifies,  by  code,  those  common  tool  sets  (not individual tools), common TMDE, special tools, special TMDE, and special support equipment required to perform the designated maintenance function.  Codes are keyed to tools and test equipment listed in Section III. f. (6)   Remarks.     When  applicable,  this  column  contains  a  lettercode,  in  alphabetical  order,  which  is  keyed  to remarks contained in Section IV.  If there is nothing in the Remarks column, there is no Section IV. B-4. EXPLANATION OF COLUMNS IN SECTION III, TOOLS AND TEST EQUIPMENT REQUIREMENTS. a. Column 1, Tools and Test Equipment Reference Code.  This code correlates with the code used in Section II, Column 5. b. Column  2,  Maintenance  Level.    The   symbol   designation   shown   indicates   the   lowest   level   of   maintenance authorized to use the tool or test equipment. c. Column 3, Nomenclature.  This is the name or identification of the tool or test equipment. d. Column 4, National Stock Number.  This is the national stock number of the tool or test equipment. e. Column 5, Tool Number.  This is the manufacturer's part number. B-3