| Code | Description | Comment | Version |
| B | Blind Sample | | added v2.4 |
| C | Calibrator, used for initial setting of calibration | | added v2.4 |
| E | Electronic QC, used with manufactured reference providing signals that simulate QC results | | added v2.5 |
| F | Specimen used for testing proficiency of the organization performing the testing (Filler) | | added v2.5 |
| G | Group (where a specimen consists of multiple individual elements that are not individually identified) | | added v2.5 |
| L | Pool (aliquots of individual specimens combined to form a single specimen representing all of the components.) | | added v2.5 |
| O | Specimen used for testing Operator Proficiency | | added v2.5 |
| P | Patient (default if blank component value) | | added v2.4 |
| Q | Control specimen | | added v2.4 |
| R | Replicate (of patient sample as a control) | | added v2.4 |
| V | Verifying Calibrator, used for periodic calibration checks | | added v2.5 |