This POS option in Options Configuration is the spacing you want on receipts. If you put a value in this option, it supercedes the entry you made in the "Print Invoices Invoice Spacing? (1-3)" option.
This option works independently of the Invoice Printer # field. The Invoice Printer # field does not have to be set to T in order to change this option.
The available settings for this option are:
1 = Single Space
2 = Double Space
3 = Triple Space
blank = Use spacing designated in the "Print Invoices Invoice Spacing? (1-3)" field.