Return to Answer

• The author of the specific post (question or answer).

  Note that the author of the post will always be notified of any new comment. You may still use it for clarity, if needed; however, if there are no comments, or only you or the author have commented on the post so far, the @name will be automatically removed from the beginning of the comment, as it adds no value. (To avoid breaking sentences, mentions not at the beginning will not be removed.)

• Any user who has a visible (non-deleted) comment on the post.

  This is usually through the @name feature. Additionally, if a user comments on their own post and there is only one other person who has previously commented on that post, then that person is also notified, even if @name is not used.

  However, if the visible comment(s) being replied to are deleted, apart from several exceptions with diamond moderator's comments in a deleted post, then the notification is removed, regardless of whether or not the recipient has already seen the notification.

• Any user who has edited the post (does not include pending or rejected edit suggestions).

• For questions: The moderator or gold badge holder who closed or reopened the question, provided they were the only one to do so. Users who have closed or reopened a question without a binding close vote (i.e. without a gold tag badge or a moderator vote), and those who bindingly voted, but other users were also involved (e.g. closed by User1, User2, and Moderator) cannot be notified.

• For questions: any user who put a bounty on the question (current or expired)

• The author of the specific post (question or answer).

  Note that the author of the post will always be notified of any new comment. You may still use it for clarity, if needed; however, if there are no comments, or only you or the author have commented on the post so far, the @name will be automatically removed from the beginning of the comment, as it adds no value. (To avoid breaking sentences, mentions not at the beginning will not be removed.)

• Any user who has a visible (non-deleted) comment on the post.

  This is usually through the @name feature. Additionally, if a user comments on their own post and there is only one other person who has previously commented on that post, then that person is also notified, even if @name is not used.

  However, if the visible comment(s) being replied to are deleted, apart from several exceptions with diamond moderator's comments on deleted posts, then the notification is removed, regardless of whether or not the recipient has already seen the notification.

• Any user who has edited the post (does not include pending or rejected edit suggestions).

• For questions: The non-moderator user who closed or reopened the question, provided they were the only one to do so. On most sites, this only includes users with gold tag badges who single-handedly closed or reopened duplicate questions. Other cases of this include closures/reopenings on Stack Overflow prior to 2009 and on Hardware Recommendations after mid-2019. If other users were also involved in the closure (e.g., closed by User1, User2, and GoldBadgeUser), no users can be notified.

• For questions: the moderator user who closed or reopened the question. Unlike the above case of non-moderator users, there are no restrictions on whether the moderator was the sole user involved in the action. Do note that this checks whether the user cast their binding vote in their capacity as a moderator, so if a user wasn't a moderator at the time but later became one they cannot be notified, and if they were a moderator but later ceased to be one, they can still be notified.

• For questions: any user who put a bounty on the question (current or expired)

• The author of the specific post (question or answer).

  Note that the author of the post will always be notified of any new comment. You may still use it for clarity, if needed; however, if there are no comments, or only you or the author have commented on the post so far, the @name will be automatically removed from the beginning of the comment, as it adds no value. (To avoid breaking sentences, mentions not at the beginning will not be removed.)

• Any user who has a visible (non-deleted) comment on the post.

  This is usually through the @name feature. Additionally, if a user comments on their own post and there is only one other person who has previously commented on that post, then that person is also notified, even if @name is not used.

  However, if the visible comment(s) being replied to are deleted, then the notification is removed, regardless of whether or not the recipient has already seen the notification.

• Any user who has edited the post (does not include pending or rejected edit suggestions).

• For questions: The moderator or gold badge holder who closed or reopened the question, provided they were the only one to do so. Users who have closed or reopened a question without a binding close vote (i.e. without a gold tag badge or a moderator vote), and those who bindingly voted, but other users were also involved (e.g. closed by User1, User2, and Moderator) cannot be notified.

• For questions: any user who put a bounty on the question (current or expired)

• The author of the specific post (question or answer).

  Note that the author of the post will always be notified of any new comment. You may still use it for clarity, if needed; however, if there are no comments, or only you or the author have commented on the post so far, the @name will be automatically removed from the beginning of the comment, as it adds no value. (To avoid breaking sentences, mentions not at the beginning will not be removed.)

• Any user who has a visible (non-deleted) comment on the post.

  This is usually through the @name feature. Additionally, if a user comments on their own post and there is only one other person who has previously commented on that post, then that person is also notified, even if @name is not used.

  However, if the visible comment(s) being replied to are deleted, apart from several exceptions with diamond moderator's comments in a deleted post, then the notification is removed, regardless of whether or not the recipient has already seen the notification.

• Any user who has edited the post (does not include pending or rejected edit suggestions).

• For questions: The moderator or gold badge holder who closed or reopened the question, provided they were the only one to do so. Users who have closed or reopened a question without a binding close vote (i.e. without a gold tag badge or a moderator vote), and those who bindingly voted, but other users were also involved (e.g. closed by User1, User2, and Moderator) cannot be notified.

• For questions: any user who put a bounty on the question (current or expired)

Keep in mind that the question and answers are all considered independently. For example, if Alice was the author of the question, then you cannot notify her by commenting on Bob's answer (unless Alice also participated in that answer). Similarly, you cannot notify Bob by commenting on Alice's question (unless Bob participated in the question).

Users without an account on the site (i.e. if their name shows up without a link, such as deleted users) will not show in the autocomplete, as there's no active account to which to send the notification.

If you are using the mobile apps, there is no autocomplete feature when typing; however, you can still autocomplete users who commented by tapping on an existing comment and using the reply button at the top. (The button won't show in the above case of the commenting user not having an active account on the site.)

An exception is the case when the first @name either matched nobody, or matched the post's author (and thus isn't necessary); in this case, the next @name will be checked. Note that these checks only apply to the first @name, not subsequent ones; if the first one matches someone, and there are multiple @name mentions (or any text of the form @something), the comment will still be blocked.

Keep in mind that the question and answers are all considered independently. For example, if Alice was the author of the question, then you cannot notify her by commenting on Bob's answer (unless Alice also participated in that answer or is following the answer). Similarly, you cannot notify Bob by commenting on Alice's question (unless Bob participated in or is following the question).

Users without an account on the site (i.e., if their name shows up without a link, such as deleted users) will not show in the autocomplete, as there's no active account to which to send the notification.

An exception is the case when the first @name either matched nobody or matched the post's author (and thus isn't necessary); in this case, the next @name will be checked. Note that these checks only apply to the first @name, not subsequent ones; if the first one matches someone, and there are multiple @name mentions (or any text of the form @something), the comment will still be blocked.