I created two scenarios below with line item display flag and without this flag to explain this function. But first, you’ve to understand the difference in the entry view and GL view.
The entry view is where you can see documents in the subledgers AP and AR. The GL view is where you can see these documents independent of subledgers. Always will be displayed by GL.
When a GL account is created, you’ve the option to mark the “Dislpay line items” checkbox. Technically, if the flag is marked, these line items will be copied to subledgers or entry view. If does not has the flag, e.g BSIK or BSAK (opened line items and cleared line items tables for vendor) won’t displayed this line items and FBL3N or FAGLL03 in the entry view can’t be displayed. BSIK and BSAK tables for vendor side, this can be applied for customer o GL side.
FBL3N has only entry view. FAGLL03 has two types of views: entry view and GL view. FAGLB03, FS10 and FS10N are displayed the balance independent of the flag. But to display line items by FS10 and FS10N. i.e, transactions that are used with entry view will be checked in the master data GL account if the flag is marked or not. If does not marked, line item won’t appears.
In the FAGLL03 tcode when GL view is selected is independent of flag in the data master GL account because this transaction research BSEG table to find line items. This happens too with FAGLB03 to dislplay line item because this transaction use only GL view.
Check the screenshots below:
Without flag GL account 2010000000 and with entry view:
Without flag GL account 2010000000 and with GL view:
With flag GL account 2010001000 and entry view:
If you created a GL account without this flag and after some time you want to activate it, you’ve to run RFSEPA01 program or FAGL_ACTIVATE_IT tcode. This transaction will copy the line items from BSEG table to BSIK and BSAK tables for vendor side. But, also can be applied for customer or GL side.
But before to run or activate this flag, read the program documentation.