Chart of Accounts

Apologies if this question is elementary, but after I setup my Chart of Accounts (COA), I added non-posting accounts for Begin-Total and End-Total. When I went to add an additional account and indent this account, I received an error that one non-posting account that I setup did not have a Begin-Total, only an End-Total. This account was the EBITDA account which is nothing more than an End-Total that totals my Gross Margin and OpEx.

As such, NAV 16 won't let me indent this new account. Curious to understand why.