Citroen Xsara - Remote control

Hello friends, I open this post to tell you a trick that I have discovered with the remote control of Citroen Xsara Exclusive model (I don't know if it is worth other models). The command of mine has three buttons in the key, one to open, another to close and another for trunk (apart from the key to take the key).
When we change the stack, or the remote control is devoted to reprogram it. Following the instructions of the manual you have to contact and without starting the vehicle click and hold one of the buttons for a few seconds to program again.

What I have not read anywhere and if I have checked, it is:
if we put contact and without starting we keep the trunk button, once the horn sounds (a short touch), this indicates that the trunk has been blocked, I mean that it only opens when pressing that button of the control, does not open with the insurance of the rest of the doors. To open we have to press the ultimate button of the key (the trunk) and then the control of the trunk door.
If we put contact again and hold the control boot button again, now you will give two small touches. This indicates that the trunk unlocked and opens and closes with all the car insurance (even with the key) without specifically touching the control button that corresponds to the trunk.

I rectify what has been said above, the normal trunk control is a kind of electric button that we squeeze when pulling the door up, the option of blocking the trunk deactivates it from the car by computer and activates it in the remote control.
If we have the blocked trunk, it only opens with the remote control, it does not influence to press the closure of the trunk.
Advantages: The trunk lock is not activated every time we open and close the doors (in theory it will break less.
Disadvantages: If we mistaken the trunk button in the remote control, we will wear the trunk open without knowing it.
But it is good to know because if the trunk cannot be opened normally, it may have been activated the blocking option.