In a manual process, when the accountant closes the year, they zero all the revenue and expense accounts with journals to 9000. Then they zero 9000 with a journal to Retained Earnings in the balance sheet.
9100 is for the Balance sheet.
Does Tryton need to use intermediate accounts like this for closing a fiscal year?
Should accounts like this be included in a supported chart of accounts for account_ch and other countries?
There is a wizard called Balance Non Deferral in Tryton which automatically creates this account move balancing all the expenses and revenue accounts to a selected account
Normally this account is used for balance sheet, so in your case probably the 9100 account should be used.
Yes, such account should be included.
The account chart should be designed in a way that the balance sheet is always correctly computed, no mather if the wizars have been executed or not.
To achieve it, we normally include the income statement types as child of the Results account type (the one linked to 9100 account)