What are the code and description of the most frequent behavior incident type?
SELECT T1.incident_type_code ,  T2.incident_type_description FROM Behavior_Incident AS T1 JOIN Ref_Incident_Type AS T2 ON T1.incident_type_code  =  T2.incident_type_code GROUP BY T1.incident_type_code ORDER BY count(*) DESC LIMIT 1
most frequent behavior incident type refers to MAX(count(incident_type)); code refers to incident_type_code; description refers to incident_type_description; joining tables refers to JOIN; matching columns for join refers to ON T1.incident_type_code = T2.incident_type_code;