;doc: amount formatting: edits (#2115)

hledger/hledger.m4.md

@@ -4345,30 +4345,31 @@ file.
 
 If you're wondering why your `print` report sometimes shows trailing
 decimal marks, even when there are no decimal digits; it does this to
-disambiguate [ambiguous amounts](decimal-marks-digit-group-marks)
+disambiguate [ambiguous amounts](#decimal-marks-digit-group-marks)
 (amounts which have one digit group mark and no decimal digits),
 allowing them to be re-parsed reliably.
 
 More generally: hledger output falls into three rough categories, which
 format amounts a little bit differently to suit different consumers:
 
-**1. "hledger-readable output" - should be readable by hledger and by humans**
+**1. "hledger-readable output" - should be readable by hledger (and by humans)**
 
-  - It is produced by reports that show full journal entries: `print`, `import`, `close`, `rewrite` etc.
+  - This is produced by reports that show full journal entries: `print`, `import`, `close`, `rewrite` etc.
   - It shows amounts with their original journal precisions, which may not be consistent.
   - It adds a trailing decimal mark when needed to avoid showing ambiguous amounts.
-  - It can be parsed reliably.
+  - It can be parsed reliably (by hledger and ledger2beancount at least, but perhaps not by Ledger..)
 
 **2. "human-readable output" - usually for humans**
 
-  - It is produced by all other reports.
+  - This is produced by all other reports.
   - It shows amounts with standard display precisions, which will be consistent within each commodity.
-  - It can show ambiguous amounts.
-  - It can be parsed reliably in the context of a known report (because of consistent style).
+  - It shows ambiguous amounts unmodified.
+  - It can be parsed reliably in the context of a known report
+    (when you know decimals are consistently not being shown, you can assume a single mark is a digit group mark).
 
 **3. "machine-readable output" - usually for other software**
 
-  - It is produced by all reports when an output format like `csv`/`tsv`/`json`/`sql` is selected.
+  - This is produced by all reports when an output format like `csv`, `tsv`, `json`, or `sql` is selected.
   - It shows no digit group marks.
   - It shows a period decimal mark (.) when there are decimal digits.
   - It can be parsed reliably.