@ mentions don't always display a user
113721
Why comment reply auto-completion feature (@) sometimes doesn't work?
58852
Using @ signs in comments without invoking comment replies?
147193
Should the site prompt new users to include an @name in comments?
84347
Why my tweet is not appearing on the timeline of the person I am following?
153630
Names of close-voters are not visible in the post notice but in the revision history and timeline
48769
Improper pagination of user search
51186
Displaying the username of the user who created the node in the node template file
110573
Rep in User Dropdown doesn't match rep in User Profile sometimes
42053
How can I exclude disabled users from my user profile synchronization?
84734
Does there exist a user with this role?
12551
Reputation Activity in User Dropdown Incorrect/Inconsistent?
119727
Notify users when they are mentioned (on meta)
55873
Significance of the users like 'user'
84994
Make searches for user:xxx work for deleted users as well
128064
Is the @reply in a comment to the editor of a post broken?
24018
Are there plans to get the @ name completion working on the mobile website?
76476
Change all @username references in comments when a user changes their name?