It is necessary to express reserves when a parcel shows traces of damage. If the box is badly damaged, unless you are certain that the items are in perfect condition, refuse it.
If the box is not very damaged but has suffered a shock, do not hesitate to specify it through precise and detailed reserves such as "upper left corner crushed", "wet box". An imprecise note such as "subject to unpacking" has no value and does not allow you to take recourse against the carrier.
As far as possible, check the contents of the package. If an item is damaged, these reservations must be communicated to LDLC within 72 hours from delivery (an email or phone call is sufficient) and confirmed at the same time to the carrier by registered mail with acknowledgement of receipt. This letter is mandatory in such circumstances.