I noticed that it doesn't turn off for non-Admins despite disabling it in SMF.
This is a potentially dangerous situation as anybody could introduce malicious javascript so
i would like SP to honor the SMF setting and strip off the <html></html> markup.
see
https://simpleportal.net/index.php?action=post;msg=73186;topic=14571.0SMF already supports this flag selection via
Admin > Post and Topics > Bulletin Board Code > Enable basic HTML in posts checkbox