Sometimes it may not be advisable to include every stock item in the vocabulary. These items are described as NIVs (Not in the vocabulary). The NIVs include:
- Machine spares rarely required: these items should be kept out of the stores vocabulary since they are only purchased when a need arises. They are described as ONIS (only when needed items).
- Items of non-repetitive nature: These are items which are needed at certain prescribed intervals e.g. 1-5 years 2-3 year etc.