[akapulko2020]

Thanks a lot for the helpful links!
Is there any way of knowing what kind of PDF I have?

Originally Posted by ludovicus

akapulko-

The little squares occur when the font in the reader does not contain the specific character.

You may need to embed the Russian font on the .epub. Check the following threads to see if they help:

https://www.mobileread.com/forums/showthread.php?t=61587

https://www.mobileread.com/forums/showthread.php?t=36361


There is also a way to transfer the font to the reader (which will make the .epub file smaller), but the thread currently eludes me.

On your other issue, some PDF's are actually images (as opposed to reflowable text). The text size of these will not change.

Hope this helps!

Ricardo


PS- If you speak Russian and want to change the Reader's language to it, there is a "Russification" hack:
https://www.mobileread.com/forums/showthread.php?t=65336