“Thrand said he had two young thralls to sell him. Rafn answered that he would not buy them before he saw them. Thrand led forward the two boys; their hair was cropped, and they were in white coats (kulf)” (Flateyjarbók, i.).
“Almstein thrall had many children. ‘Now I think it is thy kin, Úlf, as Almstein was thy grandfather, but I am Hálfdán’s grandson; thy family has got hold of the king’s property, as can be seen, by ale-service and other outfittings. Now take here the white kirtle which my grandfather Hálfdán gave thy grandfather Almstein, and therewith take thy family name, and be a thrall henceforth; for it was decided at the Thing, when Hálfdán got a king’s name, that thy grandfather should wear the kirtle, and the mother of his children came to the Thing, and all his children put on clothes of the same kind, and all their offspring had to do the same.’ Harald had a white kirtle carried before the eyes of Úlf, and sang:—
Knowest thou this kirtle?
Thou hast to pay the Skjöldung a cow,
And a full-grown ox
Thou hast to pay the Skjöldung;
A pig and a fattened goose
Thou hast to pay the Skjöldung;
Children and all which thou earnest
Thou hast to pay the Skjöldung.”