When creating cost plan details you have to option to Populate from Team or Task Assignments create a manual plan and enter lines manually or you can do a combination of both.
How can you tell which lines were auto populated vs which were manually entered?
Release : 16.0
Component : CA PPM SAAS FINANCIAL MANAGEMENT
To find the answer you would need to query the fin_cost_plan_details table and also know the internal plan_id.
You can find the internal plan_id in the URL and it will be similar to '...plan_id=5005001'
You can then run query
SELECT * FROM fin_cost_plan_details WHERE plan_id = <Enter plan_id>
SOURCE: RESOURCEPLAN = Populated automatically
SOURCE: COSTPLAN = Line entered manually in the cost plan.
SOURCE: ACTUAL = These come from 'unplanned' lines in the cost plan and post to the table when the Update Financial Plan Actuals and Forecast job runs or when opening a plan in MUX.
'Unplanned' lines are actual costs done through manual transactions or XOG where there is not already a matching grouping attribute row.
In Classic Clarity, you could not edit these cost plan lines. Now in MUX once the job runs or you go the plan, this line gets added to the fin_cost_plan_details table and is editable.
Reference