An aqueous ink comprising water, a water-soluble organic solvent and at least two pigments. A method includes receiving precoding information and applying precoding matrix at the sender based on the precoding information. A cavity portion is formed between the chuck top and the base portion of the support body. The housing 1 is allowed to be inserted into the mounting hole under the condition that the pawl is directed to a specific orientation, and, after insertion, is turned through a specific angle.