A small notebook is stashed within Yanko's clothing. Inside, a myriad of scrawls, sketches, and notes adorn the crumpled pages. Among the disarray, one page seems to have been written with more care. It is on this page that the following can be read.
—Translated from Czech—
I think these three posts sum it up nicely. Especially the point about humiliating them in-game in an out of character manner. While that might not be your intention, it can be quite horrible for the other person. Also, if you are mainly noticing their errors because of questions that you are asking, consider not asking those questions. I'm not saying that their lack of knowledge won't shine through in other situations, but it at least reduces the impact. It also allows them to continue having fun, along with everyone else around.
Furthermore, sometimes it isn't even a lack of effort or research. A lot of people, myself included, have never heard of a 'MOS' and wouldn't have a clue that it might be an important thing to know. It might be obvious to you, someone who is in the military, but for the rest of us—we don't know what we don't know. It's easy to take your personal knowledge for granted.
If you have an issue with someone's lack of knowledge, PM them some tips or link them to a guide or two.