doc update

ledger.texi

@@ -2610,6 +2610,7 @@ For this entry, Ledger will figure out that $-23.00 must come from
 * Accounts and Inventories::    
 * Understanding Equity::        
 * Dealing with Petty Cash::     
+* Working with multiple funds and accounts::  
 * Archiving previous years::    
 * Virtual transactions::        
 * Automated transactions::      
@@ -3125,7 +3126,7 @@ Clear as mud?  Keep thinking about it.  Until you figure it out, put
 @samp{-Equity} at the end of your balance command, to remove the
 confusing figure from the total.
 
-@node Dealing with Petty Cash, Archiving previous years, Understanding Equity, Keeping a ledger
+@node Dealing with Petty Cash, Working with multiple funds and accounts, Understanding Equity, Keeping a ledger
 @section Dealing with Petty Cash
 
 Something that stops many people from keeping a ledger at all is the
@@ -3156,7 +3157,87 @@ the target account:
 This way, you can still track large cash expenses, while ignoring all
 of the smaller ones.
 
-@node Archiving previous years, Virtual transactions, Dealing with Petty Cash, Keeping a ledger
+@node Working with multiple funds and accounts, Archiving previous years, Dealing with Petty Cash, Keeping a ledger
+@section Working with multiple funds and accounts
+
+There are situations when the accounts you're tracking are different
+between your clients and the financial institutions where money is
+kept.  An example of this is working as the treasurer for a religious
+institution.  From the secular point of view, you might be working
+with three different accounts:
+
+@itemize
+@item Checking
+@item Savings
+@item Credit Card
+@end itemize
+
+From a religious point of view, the community expects to divide its
+resources into multiple ``funds'', from which it expects to make
+purchases or reserve resources for later:
+
+@itemize
+@item School fund
+@item Building fund
+@item Community fund
+@end itemize
+
+The problem with this kind of setup is that when you spend money, it
+comes from two or more places: the account and the fund.  And yet, the
+correlation of amounts between funds and accounts is rarely
+one-to-one.  What if the school fund has @samp{$500.00}, but
+@samp{$400.00} of that comes from Checking, and @samp{$100.00} from
+Savings?
+
+Using a traditional finance package would require that money reside in
+only one place.  But there are really two views to the data: from the
+account point of view, you want one set of reports; from the fund
+point of view, another set entirely -- and yet both sets should
+reflect the same expenses and incoming.  It's just where the money
+``resides'' that differs.
+
+This situation can be handled using virtual transactions to represent
+the fact that money is moving to and from two kind of accounts at the
+same time:
+
+@smallexample
+2004/03/20 Contributions
+    Assets:Checking                    $500.00
+    Income:Donations
+
+2004/03/25 Distribution of donations
+    [Funds:School]                     $300.00
+    [Funds:Building]                   $200.00
+    [Assets:Checking]                 $-500.00
+@end smallexample
+
+The use of square brackets in the second entry ensures that the
+virtual transactions balance to zero.
+
+Now money can be spent directly from a fund:
+
+@smallexample
+2004/03/25 Payment for books (paid from Checking)
+    Expenses:Books                    $100.00
+    Assets:Checking                  $-100.00
+    (Funds:School)                   $-100.00
+@end smallexample
+
+When reports are generated, by default they will appear in terms of
+the funds, income and expenses.  If the @option{--real} option is
+used, the report is in terms of the accounts.  If more asset accounts
+are needed as the source of a transaction, just list them as you would
+normally, for example:
+
+@smallexample
+2004/03/25 Payment for books (paid from Checking)
+    Expenses:Books                    $100.00
+    Assets:Checking                   $-50.00
+    Liabilities:Credit Card           $-50.00
+    (Funds:School)                   $-100.00
+@end smallexample
+
+@node Archiving previous years, Virtual transactions, Working with multiple funds and accounts, Keeping a ledger
 @section Archiving previous years
 
 After a while, your ledger can get to be pretty large.  While this