Im not completely sure of the numbering system for British Banknotes however... if you look at the right serial... it does seem that the DA10 is spaced separately from the 000001. Making the Serial DA10-000001, where DA10 seems to be something like a prefix.
The note below was described as a high serial number so this sorta supports the above interpretation.
{http://img94.imageshack.us/img94/8901/t2ec16vyke9s7tw3ktbrgms.jpg:http://img94.imageshack.us/img94/8901/t2ec16vyke9s7tw3ktbrgms.th.jpg}
Nice Note, Thanks for sharing