This is the 6676th most frequent Russian word.
ofac
The word "офац" does not exist in Russian; it may be a typo or misinterpretation.
'о' again signifies 'about', describing the subject matter of the book.
Ты читал книгу о животных?
Have you read the book about animals?
Here, 'о' translates as 'about' and introduces the topic of importance.
Я слышал, что люди часто забывают о важности мелочей.
I heard that people often forget about the importance of small things.
'о' means 'about' here, specifying the subject of conversation.