Security guards' skill category depends on the nature of their job. Someone solely responsible for opening and closing the gate may be in an unskilled category. Someone responsible for maintaining the visitors' register, records of weighing machines, loading and unloading activities, allotment of company cars, etc., may be semi-skilled. A security supervisor, who is responsible for the overall security of the organization, may fall into the skilled/highly skilled category.
Regards, S K Bandyopadhyay (WB, Howrah)