Use @mentions in a comment to get someone's attention, like for feedback or for more information, exactly where you want the help.   Sign-in to Microsoft 365 with your work or school account, and go to a document that's saved in a SharePoint library or OneDrive for work or school.   Note: For this feature to work, you'll need to be signed in to Outlook on your PC.   Add a comment.   Type @ and the first few letters of the person's first or last name, and then pick the name you want. If they don't already have permission to open the document, you'll be asked to share the document with them.   Tip: To be more casual, feel free to delete everything except the person's first name in the @mention. To include more people, type @ again and mention someone else.   Everyone you @mention will receive an email notification with a link that takes them directly to the comment where you mentioned them.

With Planner, users can:  Create new plans, assign tasks, and share files with others. Organize teamwork and collaborate on projects in a simple, visual way. Chat with others to make sure you're on the same page. Keep track of your team's progress and stay on top of your work—from anywhere, on any device.   To find Microsoft Planner, just login to https://office.com and choose to view all available applications:     Want to see a quick video tutorial?  Click the video below for an overview from Microsoft: Microsoft Planner Quick Guide     Create a Plan     Select New plan in the left pane. In the New plan window, type a name for the plan. Choose the link to Add to an existing Microsoft 365 Group (such as a Microsoft Team) or skip the link if you want to create a new group. Make the plan public if you want it to be visible to everyone in the organization.  Or, make it private if you want only plan members to see it. Select Create plan.   Add People to a Plan     Select Members in the upper-right corner of the Planner window. Begin typing the name or email address of a person that you want to add to the plan. Select the person's card when it appears.   Add Tasks to a Plan   Select + Add task. Select Enter a task name and type the task name.  In the picture above, we’ve named the task “Level Up – GSD” Do either of the following: Press Enter to create a task without a due date or assignment. Enter a due date and/or assign the task. Then select Add Task to create a task with a due date.   View Plan and Make Updates By default, plans can be viewed by the Board, Charts, and/or Schedule.     You'll automatically receive email notifications when tasks are assigned to you, and when they're due.   Done with a Task? To quickly mark one of your tasks as Completed, point to it and select the check mark.