Cotton linters pulp, which generally has a high alpha cellulose content (98 to 99 % by weight) and a very low ash content (approximately 0,05 % by weight), is distinguishable from cotton linters merely compressed in the form of sheets or slabs falling in subheading 1404 20 00 by the fact that its fibres, which have been cooked under pressure for several hours in a solution of caustic soda, are more or less digested, whereas the fibres of cotton linters of subheading 1404 20 00, not having undergone the same process, usually retain their original structure and length.