Minor changes are allowed. For example if some profiles (which you used in your initial design) are not available in your country you can change the profile. Adding or removing elements is not allowed. At the moment it is not regulated in the rules (there is no certain penalty for this) but during the competition we will check the accordance of final design to initial design. In case of problems jury will decide the penalty. All the changes to your initial design should be coordinated with us. We evaluate your request and circumstances and decide whether it would be fair to other teams.