4.1 Communications from the opposition division; reasoned statement 

Where necessary, any communication to the patent proprietor must contain a reasoned statement. This also applies to any communication to other parties which is communicated to the proprietor of the patent for information only. A reasoned statement will usually not be required if the communication concerns only matters relating to form or if it contains no more than self-explanatory proposals. Where appropriate, all the grounds against the maintenance of the European patent are to be given in the communication.