We have global variable sql_mode set to STRICT_ALL_TABLES(mysqld.cnf).
But someone changes this variable on session level, and from time to time we have problem with data in our database.
And there is no ability to ban changing sql_mode on session level.
I think many others have same problem, and it could be good decision to have some mysqld.cnf parameter(global variable) than allow to ban changing sql_mode on session level.
Actually, great decision is to have ability to ban setting session variables listed in some global variable, for example 