Discussions Overview
An @mention brings a specific person into a thread: the expert who knows the answer, the colleague who asked the same question last month, the owner of the system you are describing. In Discussions you mention someone by typing @ and a few letters of their name in any post — a new topic, a reply or an edit — and picking them from the suggestions. The mention is shown as a highlighted name in the text and is recorded in the Mentions column of the item, from where the notification flow of your site can pick it up and email the person.
Mentions are one of the features the classic SharePoint Discussion Board never had; together with subscriptions (see KB10404. Following Boards and Topics: Subscriptions and Digest Frequency) they are what makes a forum move.
Mentioning someone
- In the editor, type
@at the start of a line or after a space, followed by the first letters of the person's name — for example@ann. - After a short pause the suggestion list appears below the editor with up to eight matching people, each with their name and email address.
- Pick a person:
- with the mouse — click the entry;
- with the keyboard — move the highlight with ↓ and ↑ and press Enter or Tab.
- The typed
@annis replaced by the full display name —@Ann Lee— followed by a space, and you continue writing.
Press Esc to close the list without inserting anything; typing a space also ends the search, because a mention query cannot contain spaces. You can mention as many people as you like in one post.
📝 Note
The search starts after at least one character following @ and looks the text up in the people picker of SharePoint — the same service that resolves names in a Person column. It returns individual users only; groups, distribution lists and plain email addresses are not offered. Searching for a part of the surname or the email alias works as it does in the people picker.
How a mention looks
In the published post the mention is a bold link that reads @Display Name. Clicking it opens a new email to the person in your mail client when their address is known. The mention keeps this appearance after the post has been edited — it is part of the text of the post.
Technically the editor writes the mention as a link with a data-mention-id attribute that holds the site user id of the person. When you post or save, the web part collects these ids and writes them to the Mentions person column of the topic or reply. The flow that sends the notification therefore does not need to parse the HTML. If the person had never visited the site before, mentioning them adds them to the site's user information list — this is standard SharePoint behaviour and does not grant any permissions.
Editing a reply re-reads the mentions from the new text: a name you delete disappears from the Mentions column, a name you add appears in it. Typing @Somebody by hand, without picking an entry from the list, produces plain text and no mention.
Who can be mentioned
The suggestion list offers the users that the people picker of your tenant finds — in practice, the people in your organization's directory, including guests who were invited to the tenant. The list is not limited to people who already have access to the site.
❗ Important
A mention does not share anything. If you mention a person who cannot open the site, they may receive a notification but will not be able to read the post. Before you bring in someone from outside the team, make sure a site owner has given them access to the site — see KB10408. Permissions in Discussions: Who Can Read, Post and Moderate.
Anyone who can write on the board — users with the Add items permission — can mention; readers have no editor and therefore no mentions. A mention inside a post that is waiting for approval is stored like any other, so the flow can decide whether to notify before or only after the post is approved.
From a mention to an email
The web part itself does not send email. It records who follows what and who was mentioned where, and a Power Automate flow deployed by the site owner does the sending. For mentions the contract is simple:
- the event source is a created or modified item in
Discussions TopicsorDiscussions Postswhose Mentions column contains people; - every mentioned person receives the email, regardless of whether they follow the board or the topic and regardless of their digest frequency;
- the email links to the topic through the
?topic=<Id>parameter of the page that hosts the web part; - a user cannot switch mention notifications off — removing subscriptions stops digests, not mentions.
The flow template is not yet shipped with the preview; until a flow is configured on the site, mentions are recorded but no email is sent. The complete contract, including events, recipients and frequencies, is in KB10414. How Notifications Work in Discussions: Subscriptions, Mentions and Power Automate.
💡 Tip
Mention sparingly and precisely: one person who can actually answer is worth more than five who are copied for information. If a whole team should see a board, ask them to Follow it instead — each member then chooses their own frequency. No Microsoft Graph permissions are involved in any of this; the people search and the Mentions column are plain SharePoint, see KB10413. API Permissions and Admin Consent for Discussions.
