Operational Test Code (OTC)
A one position numeric code that indicates special procedures must be performed on an item of supply while under care-in-stores or as a part of the issue process. In accordance with DOD 4100.39-m, volume 10, table 123.
Optional Procedure Indicator Code
A one position alpha code that indicates the allowable deviations from the prescribed requirements. In accordance with DOD 4100.39-m, volume 10, table 182 and MIL-STD-2073-1E, appendix j, table j.viiia.
Order Of Use (OOU)
A three position alpha code denoting the interchangeability and substitutability (i&s) relationship of a national stock number within a service/agency i&s family. The first two positions indicate the i&s order of use subgroup code and the last position indicates the order of use sequence code within subgroups. Code a indicates the most preferred item and will be ranked alphabetically based on preference. In accordance with DA PAM 708-2, paragraph 2-17.