This method was frequently used prior to the ubiquity of dummy tokens. XLNet was the paper that introduced me to this idea. I believe it’s been in PyTorch since 2019/2020. I would not be surprised if someone finds an earlier reference.

I’m surprised by the pompousness in the OP. Especially about something that most people who do transformer research understand. I’m also surprised that so many in the replies are taking the position of “this is what research should look like” when this is clearly an example of why research doesn’t work like this. Peer review is good for many things and one of those things is saving yourself some embarrassment.