Is it common to have ink markings on the top side of unfinished hardwood flooring?

https://imgur.com/sPSa0I4

The bottom picture shows an underside sample. It seems like nothing to worry about and it'll just sand off, but I'm only seeing unmarked boards on youtube. I wanted to make sure it's not a factory mistake, or something that might show through after I stain the wood. I've installed prefinished before but my first try at unfinished.

These marks are for identifying the mill, and specie. Some mills use stickers that peel off. Light sanding to get any over wood smooth ought to remove the marks.