Foreign visuals on walls

Hi,

What is the legality of foreign visuals (i.e. things that are not the letters H, S, or U and not the color white) on walls? I understand that heated victims are covered usually with white paper, however in the regional competition I was at they were also secured with painters tape to dissuade visual detection of thermal victims. Would this kind of action be legal at international and if so what is the limit of foreign visuals on walls?

Thanks

Dear DeLuXe,

The walls will be white or close to white.

We may use some form of tape to fasten the victims, but the purpose will be to fasten them, not to confuse robots. So we will do our best to keep it discrete and hidden.

// Fredrik Löfgren