A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
For questions about the 10th anniversary of Stack Overflow, occurring in the fall of 2018.
For questions related to the 15-character-minimum threshold for comments
To report instances when you were forbidden some access on Stack Exchange, but you think you should have access.
For reporting 404-Not Found errors you've encountered on StackExchange sites or discussing the error page itself.
When the web server taking too long an interval of time between the establishment of an IP connections - between the client (from web browser - request is going) and server and receipt of any data on …
For questions about the HTTP 418 status code when returned by a Stack Exchange site
a page displayed on Stack Exchange sites in the event of an internal server error.
Policies and practices for determining when a question has been abandoned and what to do about it.
For questions relating to the Stack Exchange 'About' page, now also referred to as the 'tour' for new users.
for questions concerning actions leading to bad behaviors or bad purposes, considered or suspected to be against Stack Exchange policies or the collaboratively philosophy of any Stack Exch…
the answer the question owner thought best met their needs. This tag is for discussing issues related to accepted answers, not indicating that a question has an accepted answer.
the percentage of questions for which the user has accepted an answer.
Questions that discuss the usability of Stack Exchange sites by people with disabilities.
For questions relating to community and moderator accountability. Specifically, this is for highlighting current processes, and getting feedback on how to do the right thing for the rest of the group.
related to a completely destroyed user account. (This is in contrast to a user account that is simply deleted).
the process of regaining access to your Stack Exchange data after you lost control over your original identity.
the act of temporarily blocking the account of a specific user.
A dropdown containing recent reputation, badges, and privileges earned across all Stack Exchange sites
For feature requests and bug reports related to Action Buttons on the SE network (specifically, buttons for actions such as "Post Your Question", "Post Your Answer", "Add Comment", etc.)
for questions about the activity tab. The activity tab is found in the user profile and gives access to several categories.
For questions about the two badges, Enthusiast (silver) and Fanatic (gold), awarded for site activity.
The drop-down, accessible by hovering over your username, that shows recent badges, reputation events and basic statistics.