The ButSec extension template is used for setting additional security in procedures at a security level different than the procedure itself.  This is required to stop routine code calls, running embedded code, etc that requires tighter security.  It has its own switch to disable, but also follows the Procedure's 'Disable Security Checking for this Procedure' switch.  It does not follow the Procedure switch when installed on the Main Frame or First procedure as the procedure security is disabled to call the logon.

Select the button you want to add security too, and the default security level required.