Ted Greiner's observations about feeding terminology are appreciated. A functional definition for <complementary food> is provided, for example, in Art. 3 of the International Code of Marketing of Breast-milk Substitutes: <Any food, whether manufactured or locally prepared, suitable as a complement to breast milk or to infant formula, when either becomes insufficient to satisfy the nutritional requirements of the infant. Such food is also commonly called <weaning food> or <breast-milk supplement>. In chapter 4, on complementary feeding, of <Infant feeding: the physiological basis> (WHO, 1990), <weaning process> is described as the <progressive transfer of the infant from breast milk to the usual family diet>. Thus, for the purposes of the definition, weaning *begins* when the infant receives food *other than* breast milk, and *ends* when the infant ceases to receive any breast milk at all, that is when the child is completely *weaned*. Some of the typical remarks we in WHO have heard in recent years from various cultural and linguistic points of view, notably Middle Eastern and Scandinavian, suggest, as Ted noted, that the [equivalent] words <wean> and <weaning> are inappropriate in some environments, since they are viewed a little like a tap that is on one minute and off the next, and therefore have none of the subtle, *gradual* flavour of the above definition of <weaning process>. On/off would, of course, be inconsistent with WHO's feeding recommendation, which is to promote breast milk as the *exclusive* source of nourishment for the first 4 to 6 months of a child's life, and thereafter continued breast-feeding, together with nutritionally adequate and safe *complementary* foods, for up to two years of age or beyond. Jim Akre, Nutrition unit, WHO, Geneva