Indicates that the feature request will not be implemented or the bug will not be fixed as a result of this question.
A feature request or bug report is considered declined if the report is reviewed and the site developers disagree that the feature should be implemented or the bug should be fixed.
In the case of bugs, this usually comes up because the bug is not caused by the software that powers the sites themselves - such as if the problem is with the browser being used. If it would be more effective for the developers of the browser or tool causing the problem, the report will generally be declined. This is also the case if the bug is specifically caused by a browser or tool that is unsupported by the sites.
It can also come up if the bug report is determined to be valid (i.e., not status-bydesign), but the team has decided not to fix the bug for technical or performance reasons, i.e. that fixing the bug would lead to further performance issues or introduce other bugs. The team can also decline to fix a bug if the current (not as per design) behavior is considered preferred and the design is to be changed to accommodate it, though the tag status-bydesign is preferred for that case.
In the case of feature requests, this usually comes up if the request is counter to site philosophy, if the request is attempting to change behavior that is intentional or even encouraged by the system, or if the request creates greater complexity or problems in the system than it successfully solves. It can also come up if the request has merit but community members disagree with implementing it.
Once this tag has been applied to a post, it generally means that the request will not be actioned as a result of the question to which it is applied - therefore, continued activity on the post will not change the outcome, since it is no longer being monitored by staff and it can no longer be escalated using the status-review tag.
You can, however, make a new request asking for a previous declined request to be reconsidered, if you believe that the declining reason was incorrect or circumstances have changed since the time it was declined. Such requests should clearly outline and argue against the reasons for declining at the time, or at least clearly explain what has changed since the last request. If the same reasons for declining still apply to your question, it may be closed as a duplicate of the prior request as its answer addresses your question.
Status tags can only be applied by moderators and site developers.
Related: Listen to Your Community, But Don't Let Them Tell You What to Do
