Follow naming conventions:
Client and ClientInvoice, then ClientInvoiceDetail.ClientInvoice is preferred over Client_Invoice.Clients is preferred over Client.QtyAmtPwdDateInvoiced. One extra use of this is you can have generic code that enables a date control on this field.SalesTaxPct.AustraliaListA$. Avoid the following characters in your object names in SQL Server. If you do not do this, you will need to constantly identify those ill-named objects with bracketed or quoted identifiers - otherwise, unintended bugs can arise.User, Count, Group, etc. They can be used if joined with other words. See Reserved Keywords (Transact-SQL)