There is more to shovels than meets the eye (except for Chinese beauties)
Here are Irish post-war regulations but I am sure every country had similar rules.
https://www.irishstatutebook.ie/eli/.../made/en/print
Please note all this talk about shovels is totally wrong. A shovel has a long handle and a spade has a short handle.
Local language use describes a shovel or a spade by their shape, square or round - either way, in different places around the world, coal shovels and snow shovels but this is only tradition and not a manufacturers accepted desciption. In fact many people have never used the word spade for a digging instrument of any variety. Many experts, particularly gardening experts, on advice websites and hardware stores perpetuate this description. Then we have people talking about short or long shovels. Just because some technical writer who had never seen one called it a "shovel" in a manual or parts book does not make it so.
This is the important bit. Long handled shovels (or spades if you are a spade man) tend to have the blade in line with the handle for plunging and levering while standing erect - hard stuff and holes. Short handled spades (or shovels if you are a shovel man) have the blade angled for scooping and lifting - soft and loose stuff. You sometimes come upon a shovel or spade that has been fitted with the opposite handle and wonder why the thing has a useless angle. A bent spade shank and a straight shovel shank can both be exactly the same blade shape and both stamped #2.
PS Further info: The numbers refer to the size/weight not the shape. A #2 can be round or square and is the first and most common "man-sized" weight offered by manufacturers. #1, #00 and #0 are smaller garden, trench or specialist shovels/spades. #3, #4 and #5 are starting to get beyond amateur use and are made for operators with strength and skill ie concrete workers or boiler firemen.
Standard sizes may vary slightly between manufacturers but will be close to:
#2 9X12
#1 8 1/2x11
#00 7x9
#0 6x7 1/2
In the end in 99% of cases it matters not what you call it so long as you get the right size, handle length, blade angle and shape for the job in hand. Putting a long handle on a bent shank spade (round or square) is perfect to scoop sand from under the vehicle in the desert but useless for digging out of mud while putting a short handle on a straight shank shovel (square) is perfect for doing concrete grass edging but useless for filling the barrow with sand. Are they then shades and spovels?
And lastly "You can shovel some dirt out with a spade and spade the garden flat with a shovel"