690fd94f___open_books_for_an_open_world__Meaning
[Mode] T [Meaning] 
Deny execution of binaries or scripts that are writable by any other subject in the policy. This flag is evaluated at policy enable time. All binaries with execute permission that are writable by another subject (ignoring special roles) will be reported and the RBAC system will not allow itself to be enabled until the changes are made.
Grsecurity/Print version - Wikibooks, open books for an open world
Meaning