diff --git a/hledger/hledger.m4.md b/hledger/hledger.m4.md
index 526794eb4..48f2b4f53 100644
--- a/hledger/hledger.m4.md
+++ b/hledger/hledger.m4.md
@@ -651,6 +651,10 @@ This option can repeated to set the display style for multiple
 commodities/currencies. Its argument is as described in 
 the [commodity directive](#commodity-directive).
 
+hledger will occasionally make some additional adjustments to number formatting,
+eg adding a trailing decimal mark to disambiguate numbers with digit group marks;
+for details, see [Amount formatting, parseability](#amount-formatting-parseability).
+
 ## Colour
 
 In terminal output, some commands can produce colour when the terminal supports it:
@@ -1266,6 +1270,12 @@ by other reports.
 When rounding, hledger uses [banker's rounding](https://en.wikipedia.org/wiki/Bankers_rounding)
 (it rounds to the nearest even digit). So eg 0.5 displayed with zero decimal digits appears as "0".
 
+### Number format
+
+hledger will occasionally make some additional adjustments to number formatting,
+eg adding a trailing decimal mark to disambiguate numbers with digit group marks;
+for details, see [Amount formatting, parseability](#amount-formatting-parseability).
+
 <a name="transaction-prices"></a>
 
 ## Costs