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.
SQLite makes no use of subtype itself. It merely passes the subtype from the result of one application-defined SQL function into the input of another.
See also lists of Objects, Constants, and Functions.
SQLite is in the Public Domain.
https://sqlite.org/c3ref/value_subtype.html