I've seen post(s) on removing a username from a Stack Exchange post, in accordance with CC BY-SA 3.0 -- see, for example, https://meta.stackexchange.com/questions/96732/how-do-i-remove-my-name-from-a-post-in-accordance-with-cc-by-sa-3-0.
My question isn't about Stack Exchange, but about the difference between CC BY-SA 3.0 and 4.0; arXiv (preprint server) uses 4.0, and says that they will not remove material posted to their site. I couldn't find, without going into technical documents that I wouldn't understand, the difference in this respect between 4.0 and 3.0.
It seems to me that if one can remove a name from a Stack Exchange post on 3.0, if arXiv used 3.0, then one would be able to remove a name from an arXiv post; hence there must be a reasonably significant difference between 3.0 and 4.0? Am I correct?
Details can be found on the Creative Commons website: