- Subtypes are transitive, that is if A is a subtype of B and B is a subtype of C, then A is also a subtype of C.
- The term subtype is sometimes used to incorrectly to refer only to the concepts that are directly related to a parent concept via a 116680003 |is a| relationship. The correct term a directly related subtype concept is subtype child.
- Bacterial infectious disease is a subtype of infectious disease. Bacterial septicemia, bacteremia, bacterial peritonitis, etc. are subtypes of bacterial infectious disease (and thus also subtypes of infectious disease).