| Lvl | Code | Display | Definition |
| 1 |
comparable |
Comparable |
The data element is sufficiently well-constrained that multiple pieces of data captured according to the constraints of the data element will be comparable (though in some cases, a degree of automated conversion/normalization may be required). |
| 2 |
fully-specified |
Fully Specified |
The data element is fully specified down to a single value set, single unit of measure, single data type, etc. Multiple pieces of data associated with this data element are fully comparable. |
| 2 |
equivalent |
Equivalent |
The data element allows multiple units of measure having equivalent meaning; e.g. "cc" (cubic centimeter) and "mL" (milliliter). |
| 2 |
convertable |
Convertable |
The data element allows multiple units of measure that are convertable between each other (e.g. inches and centimeters) and/or allows data to be captured in multiple value sets for which a known mapping exists allowing conversion of meaning. |
| 3 |
scaleable |
Scaleable |
A convertable data element where unit conversions are different only by a power of 10; e.g. g, mg, kg. |
| 1 |
flexible |
Flexible |
The data element is unconstrained in units, choice of data types and/or choice of vocabulary such that automated comparison of data captured using the data element is not possible. |