That would be a person writing the name. Some people have very nice handwriting, so it could look like it was computer printed.
I could never write on my ponies. I feel bad about the fact they are now permanently "maimed" if they are written on, since getting pen off is almost impossible.
I wrote my name on the hooves of my ponies as a child, at least the abbreviation of it. Twice it meant straying ponies were returned safely to the mother fold
And it's not actually true they're permanently maimed, depending on the ink, because most of my childhood ponies had biro names and most of them it's worn off completely. Only a handful of them still say it now.
BUT there are ways and means to do it permanently, and the hooves are different to me than the stomach or face or anything visible when the pony is standing upright.
Just I would have lost Sky Rocket and Snowflake without the name being on the hoof, and it's kind of nostalgic for me to have the name there. I always wonder when I get a pony with a name on the hoof what adventures that pony had, because you only need to put a name on a pony if it's going adventuring somewhere outside the home.
I have a bunch from a childhood friend as well which still some of them say ALEX on the feet, and that's kind of nostalgic as well.
I would never do it now - and really cringe and hate it when people get G1 ponies signed like they're somehow 3D autograph books - but I do strongly advocate marking hooves on a restored pony. So I guess it still doesn't bother me so very much.