In Application Administration, a padlock icon next to an advanced setting represents a mandated or suggested state.
An administrator can mandate or suggest the advanced settings.
A locked padlock represents a state of mandated. If a function has a state of mandated, the system administrator has made the value of this function mandatory and unalterable; the system administrator defined the value of this function, and the client user cannot alter or override that value.
An unlocked padlock represents a state of suggested. If a function has a state of suggested, the system administrator has made a suggestion as to what the value of a function should be; the system administrator defined the value of this function, but the client user can alter or override that value.