When typing (or editing) a comment, after typing @ and the first letter of a username, we're offered the choice of usernames that were in the conversation and can input them into typing the whole username. Is the effect the same if the username comes from autocomplete and if the string is typed?

For example, in the screenshot below I have two options which both end up in the string "Pekka". Is there some difference between the two possibilities? Will one of them ping a different user than the other one?


The screenshot is taken from this answer. (I found the answer from this SEDE query. The query was posted in Tim Stone's comment in one of the discussions about comment replies for users with the same username.)

This is the question on MathOverflow Meta which lead me to asking this: Is there a way to @ exactly one of two users whose names differ, if at all, only by whitespace? (But the two questions are not the same.)

  • 3
    Whether you (manually) type the string, or use any one of the autocomplete options, only the most recent Pekka would be notified / pinged in both cases.
    – Justin
    Commented Aug 4, 2022 at 6:30

1 Answer 1


No, there is no difference. Both will produce the exact same comment text (you could verify that with SEDE and/or the API), and that's what is used by the server to create an inbox notification. Which as Justin observed, will happen for the last matching participant.

The server does not remember whether you autocompleted the username or not. In fact, the autocompletion (both the suggesting and the applying) happens entirely client side - that's probably one of the reasons it only works for commenters. You can verify that by checking the network requests in your browser, or simply by switching off your Wi-Fi.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .