Hello ~ Does "square" in "during daylight hours, a red flag should be attached to the end of the extension or load. The flag must be at least 30 centimetres (one foot) long on each of the four sides of the square" refer to the flag itself? Or does it refer to the extension or load? Thank you!
The sentence clearly, from its structure and plain grammatical construction, refers to the flag and does not refer to the extension of the load. This is also the only construction of the language that makes sense. The load would not necessarily be square and could have larger or smaller dimensions.