difficulty with grouping payment lines
in order to group invoices with credit notes, it was not possible to use the payment lines form... as only payable lines, receivable lines and to receive with mandate do not permit to see both lines at once.
Therefore it is necessary to open the accounting plan, go to the appropriate account, select the party as well as reconciliation:= all in order to be able to select the lines that need to be grouped.
It would be nice then to have in payment lines an 'all' tab that would more easily permit such an operation. That is, something like the states of invoices: draft, valid, posted, all