sqlite3_value_subtype —
Finding The Subtype Of SQL Values
unsigned int
sqlite3_value_subtype(sqlite3_value*);
The sqlite3_value_subtype(V) function returns the subtype for an
  application-defined SQL function argument V. The subtype information can be
  used to pass a limited amount of context from one SQL function to another. Use
  the sqlite3_result_subtype() routine to set the subtype for the return value
  of an SQL function.