Product graphics including ornament, cosmetic and branding have no regulatory body rules regarding location, orientation, size, colour, etc. Corporate identification practices only apply.
Product graphics including safety certification labeling UL, CSA, CE, TUV, FCC, etc. do have size and placement guidelines. Other labeling such as NiCad battery no-dispose / recycle symbols also have size implementation guidelines.
These guidelines are available from their respective issuing bodies. A product application for certification can be conditionally rejected if label symbols are inappropriately applied.