Consolidate GL-001 TradOn assessment decisions

Docs/reporting_standards.md

@@ -26,7 +26,7 @@ When a report exposes an FX rate between transaction currency and base currency,
 - whether the rate is direct or inverse;
 - the number of decimal places preserved in the export.
 
-`GL-001 General Ledger` currently defines the FX-rate field as `Currency_Rate`. This report-specific name should be preserved in GL-001 exports until the field naming convention is explicitly harmonized.
+`GL-001 General Ledger` defines the FX-rate field as `currency_rate`, following the wider field naming convention.
 
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@@ -50,6 +50,15 @@ Examples:
 - `credit_base_currency`
 - `balance_base_currency`
 
+When a detailed report needs to show rolling balances on each movement line rather than a single running balance column, use:
+
+- `initial_balance_transaction_currency`
+- `ending_balance_transaction_currency`
+- `initial_balance_base_currency`
+- `ending_balance_base_currency`
+
+For `GL-001 General Ledger`, these initial and ending balance fields replace `balance_transaction_currency` and `balance_base_currency`. The first line initial balance date is the day before `date_from`: balance sheet accounts use the account balance up to that date, while profit and loss accounts use the movement balance from the start of the fiscal year up to that date. Subsequent line initial balances roll forward from the previous line ending balance.
+
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 ## Posting status
@@ -73,7 +82,7 @@ General financial statement sign conventions:
 
 These sign conventions apply to financial statement presentation and summary reports. Detail ledger reports may define their own sign convention when required.
 
-For `GL-001 General Ledger`, debit amounts are positive and credit amounts are negative, as specified in the report definition.
+For `GL-001 General Ledger`, debit amounts and credit amounts are positive, following the current Tryton convention. Ending balances are calculated as initial balance plus debit minus credit.
 
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