and end items, and replacement of all parts in columns 2, 3, 4, and 5.
d. Symbol X. This symbol in the appropriate column indicates the lowest echelon responsible for performing
that particular maintenance operation, but does not necessarily indicate repair parts will be stocked at that level.
e. Remarks. The remarks column is used to explain why maintenance that would normally be done at a lower
echelon, is moved to a higher echelon because of some peculiarity in the construction of the end item.