I got this after breaking a dollar and when i looked closer at it i could see letters by the side of her head. I tried to take pics but it seems to come out blurry despite the digital microscope i used. I can make out an m an n and a but it and i don't know much about Canadian coins either.
I don't think that is any type of Mint Error Just some stain or faded letters that were applied post mint
I don't see any letters there. Just some random staining that kind of looks like letters. I suspect this is a case of pareidolia. Even if those really are letters of some sort, they likely were a result of transfer from contact with some kind of ink-printed material - outside the mint - so this is certainly not a mint error. I can see how it would sorta look like lettering at first glance, though.