All eight occurrences of this custom occur in Lincolnshire, seven in Kesteven and the eighth just a few miles away. It is unclear whether this is a very localised custom or another example of the erratic recording of information in Domesday Book.
The meaning of frigesoca is uncertain. Stenton described it as enigmatic and suggested that it might signify that it was a jurisdiction from which the inferior party could withdraw at will.
For more detail, see F.M. Stenton, Types of manorial structure in the northern Danelaw (1910).