Hoof markings scratched off?

[Elva]

I got Baby Yo-Yo today! Her hooves have been stamped with MADE IN, CHINA, 87 HASBRO INC. One of the hooves looks like it has previously said something, but now looks like this. Sorry about the poor photo! I remember hearing something about ponies that have had the pat pend-marking scratched off or hidden. Do any of you know anything about this? I'm just curious 

[Taffeta]

So, to boggle your mind in terms of pat pending logic.

I just went and checked my newborns. I have four in this pose - Yoyo, Moondream, and the twins Fluffy and Fleecy (in the US, Speckles and Bunkie).

The twins were released in 1988. Neither have Pat Pend on their hooves, nor any sign of it being rubbed off. It is like it wasn't there at all.

Yoyo (sold here 1990) and Moondream (sold here 1992-3) both have pat pend on their hoof. It's slightly faint but not scratched out.

I don't really know how to explain this except...Hasbro.

All four of these I got here in the UK. Yoyo and Moondream I had from new. Fluffy & Fleecy from a carboot sale. I have a bunch of Yoyos in my trade box, but can't get at them right now to check.

[Elva]

Pat Pend logic = no logic at all

[Taffeta]

Pat Pend logic = no logic at all

Pony Logic = nonexistent.