| Code | Display | Definition | 
| =  | 
Equals | 
The specified property of the code equals the provided value. | 
| is-a  | 
Is A (by subsumption) | 
Includes all concept ids that have a transitive is-a relationship with the concept Id provided as the value, including the provided concept itself (include descendant codes and self). | 
| descendent-of  | 
Descendent Of (by subsumption) | 
Includes all concept ids that have a transitive is-a relationship with the concept Id provided as the value, excluding the provided concept itself (i.e. include descendant codes only). | 
| is-not-a  | 
Not (Is A) (by subsumption) | 
The specified property of the code does not have an is-a relationship with the provided value. | 
| regex  | 
Regular Expression | 
The specified property of the code  matches the regex specified in the provided value. | 
| in  | 
In Set | 
The specified property of the code is in the set of codes or concepts specified in the provided value (comma-separated list). | 
| not-in  | 
Not in Set | 
The specified property of the code is not in the set of codes or concepts specified in the provided value (comma-separated list). | 
| generalizes  | 
Generalizes (by Subsumption) | 
Includes all concept ids that have a transitive is-a relationship from the concept Id provided as the value, including the provided concept itself (i.e. include ancestor codes and self). | 
| child-of  | 
Child Of | 
Only concepts with a direct hierarchical relationship to the index code and no other concepts. This does not include the index code in the output. | 
| descendent-leaf  | 
Descendent Leaf | 
Includes concept ids that have a transitive is-a relationship with the concept Id provided as the value, but which do not have any concept ids with transitive is-a relationships with themselves. | 
| exists  | 
Exists | 
The specified property of the code has at least one value (if the specified value is true; if the specified value is false, then matches when the specified property of the code has no values). |