The files must be in JPEG/JPG format, 8 bit, RGB, with the 1920 pixels wide and 1080 pixels high, 300 dpi. Each file should not exceed 1 MB in size. The title should be in English and the maximum length 35 characters including spaces. No special characters such as !@#$%^&*()+/?<> ''"" etc. are allowed ; only space, dash (-) and underscore ( _ ) are allowed in file naming besides a-z, A-Z and 0-9.