There has been some changes between versions from 5.10 to 5.21 but among them some of the ones we can share with you are these:
“Custom Fields” Text is now showing on new invoice window when user select 'Draft Invoices' from 'Create From' drop down list. Customers name Web interface issue with "&" symbol was addressed. (In Web) Invoice Number text box is no longer showing blank after select invoice number on 'New Credit Note' page. When “use small size for printed receipts”, Total and Subtotal section are not cutoff in Receipt PDF and Print.