Main Line in Transaction Search Criteria
Main line refers to the Primary Information field group in a transaction, as opposed to line item data entered on the transaction’s tabs.
In the following example, 
indicates the transaction’s main line data, and 
indicates the transaction’s line item data.
By default, the main line and line item data for each transaction appear on separate rows in the search results. To configure the search results to display either the main line data rows only or the line item data rows only, you can use the Main Line filter on the search Criteria tab.
If the Results tab of your search contains the * (main line) filter, the main line data rows in the search results are marked with *.
The Main Line filter is not supported for transaction searches where the type is set to Journal Entry.
The Account (Main) field represents the account that is shown in the results when the criteria include Main Line is true. For example, Account (Main) for an invoice is an accounts receivable account, but the Account for lines on the invoice are specific to the item, billable expense, or billable time.
When Main Line is set to true
When you add the Main Line filter on the search Criteria tab and set it to true (Yes), the search results display one row per transaction, whereas the line item details are omitted.
When Main Line is set to false
When you add the Main Line filter on the search Criteria tab and set it to false (No), the search results display one row per line item, but these rows may still include some of the main line data.
