Basically, the control instruments are quantitative or price-based, including price ceilings or floors and possibly a combination of the two. Controls or lack of controls may be based on size of a transaction, purpose, or category of participant. Asymmetrical treatments in regard to applicability and nature of controls are common between inflows and outflows; between outflows associated with inflows (i.e.
principal, interest, dividend, profits and sale proceeds) and other outflows; resident and non-residents; and between individuals, corporates, banks and other financial intermediaries. The instruments of control do vary from non-applicability, to total prohibition with intermediate regimes, say of approval on an automatic basis, case-by-case or simply price-based. The control may also differentiate financial instruments by their nature or ratings.