Alphanumeric patron barcodes

["Wan Lye Tim" <wanlt@xxxxxxxxxx>]

Appreciate feedback on the implications of using alphnumeric patron
barcodes.

1   What are the implications for using patron barcodes of more than 10
    alphanumeric characters while the item barcode is of 10 digits?

    For example, will system automatically recognise that they are
    barcodes?  Or, for all search using patron barcode, is it necessary to
    precede search string with the index code "b"?

2   Is there any effect on self-check machines if the patron barcode
    comprises a long string of alphanumeric characters, say 30 characters?

Thank you.

Lye Tim