;update CLI usage texts

hledger/Hledger/Cli/Commands/Print.txt

@@ -4,12 +4,10 @@ Show transaction journal entries, sorted by date.
 _FLAGS
 
 The print command displays full journal entries (transactions) from the
-journal file in date order, tidily formatted. With --date2, transactions
-are sorted by secondary date instead.
-
-print's output is always a valid hledger journal.
-It preserves all transaction information, but it does not preserve
-directives or inter-transaction comments
+journal file, sorted by date (or with --date2, by secondary date).
+Amounts are shown right-aligned within each transaction (but not across
+all transactions). Directives and inter-transaction comments are not
+shown. Eg:
 
 $ hledger print
 2008/01/01 income
@@ -33,6 +31,22 @@ $ hledger print
     liabilities:debts               $1
     assets:bank:checking           $-1
 
+print's output is usually a valid hledger journal, and you can process
+it again with a second hledger command. This can be useful for certain
+kinds of search, eg:
+
+# Show running total of food expenses paid from cash.
+# -f- reads from stdin. -I/--ignore-assertions is sometimes needed.
+$ hledger print assets:cash | hledger -f- -I reg expenses:food
+
+There are some situations where print's output can become unparseable:
+
+-   Rounding amounts according to commodity display styles can cause
+    transactions to appear unbalanced.
+-   Valuation affects posting amounts but not balance assertion or
+    balance assignment amounts, potentially causing those to fail.
+-   Auto postings can generate postings with too many missing amounts.
+
 Normally, the journal entry's explicit or implicit amount style is
 preserved. For example, when an amount is omitted in the journal, it
 will not appear in the output. Similarly, when a transaction price is