Complex subject, especially in English and without having Finereader installed!

As far as I understand, they think that Finereader is able to remember associations of some graphical patterns not only with the some specific "letter"-character but also with the any character sequence. Then, it turns out that there is special Unicode character-modifier, that being output after any letter, makes Windows to draw letter in special way, as if we are getting new characters.
About this special character:
Знак ударения — Википедия

Attached picture to demonstrate how to get to that misterious character in my Windows (which has English UI).

And my attempt to cook stressed Cyrillic vowels:
а́у́ю́
u301.png