A policy is a deliberate system of principles to guide decisions and achieve rational outcomes. A policy is a statement of intent, and is implemented as a procedure or protocol. Policies are generally adopted by a governance body within an organization. Policies can assist in both subjective and objective decision making. Policies to assist in subjective decision making usually assist senior management with decisions that must be based on the relative merits of a number of factors, and as a result are often hard to test objectively, e.g. work-life balance policy. In contrast policies to assist in objective decision making are usually operational in nature and can be objectively tested, e.g. password policy.
Turn him to any cause of policy, The Gordian knot of it he will unloose, Familiar as his garter: that, when he speaks, The air, a charter'd libertine, is still.
William Shakespeare, Henry V (1599), Act I, Scene 1.
Much as sponges soak up water and remove it from a surface, industrial sorbents collect molecules in fluids or gases. EU-funded scientists are developing carbon-based nanosorbents from vegetative waste for improved removal of industrial contaminants.