A customary due could be any customary obligation or payment incumbent upon the land. Domesday Book frequently contents itself with a general statement that customary dues were owed to the king or to the lord of a manor without specifying any one custom or service. Some that are specified are very miscellaneous. At Eardisland, in Herefordshire, for instance, it had been the custom before the Conquest to present the lady of the manor with a gift '10 ora of pence [£1.2] so that she might be happy' (HEF 1,6). The lady in question was the wife of Earl Edwin, son of Lady Godiva.
There is an interesting study of this particular manor by Mary C. Hill, The demesne and the waste: a study of medieval enclosure on the manor of High Ercall, 1086-1399 (1984). For customary dues in general, see Paul Vinogradoff, English society in the eleventh century: essays in English medieval history (1908); N. Nielson, Customary rents (1910); and Rosamond Faith, The English peasantry and the growth of lordship (1997).