When entering a journal if you type in a value that is stored in the Search Name field on a Customer/Vendor/GL Account in the Account No. field it will not find the record. Instead you have to click on "Select from full list" then "Advance view" before you can search for a search name.

For example: This would be particularly useful for Customers/Vendors that have registered company names and "trading as" company names. The Search Name can be used to store the "trading as" value which is often the company name that is used more often. When someone is entering a journal they can type in the search name and it will fill in the Account No.

I think this would probably just require the Search Name adding to the Field Groups DropDown on the Customer/Vendor/GL Account tables.