Entering variables as an invoice title in recurring invoices requires you to first:
1. Issue a proforma invoice
2. In Items Name enter the variables you wish to accomodate, you may choose from:
{{year}} {{day}} {{month}} {{previous_month}} {{next_month}} {{month_in_words}} {{previous_month_in_words}} {{next_month_in_words}} {{month+1}} {{month+2}} {{month+3}} ... {{month+11}} {{month_in_words+1}} {{month_in_words+2}} ... {{month_in_words+11}}
3. Issue a new recurring invoice
4. After generating a new recurring invoice, preview it and click edit. Check Issue VAT Invoices if you wish to issue a standard recurring invoice based on the proforma.
5. If you wish to generate a recurring invoice instantly (to test variables) set the date to current in Next invoice date.
A good example:
In Items' Name you may enter:
Website maintenance for {{month}}.{{year}}
The next invoice in sequence of recurring invoices will look like this:
Website maintenance for 04.2014