There are several proposed tags changes lingering about here on meta. I thought I'd capture them all here, each one as a separate answer, and let people vote on them. 

 - [merge `database-restoring` and `restore`][20]
 - [`Scaling` and `scalability`][1]
 - [Delete `hashbytes`][2]
 - [Make `sql-agent` a synonym of `sql-server-agent`.][3]
 - [Delete `schema`][4]
 - [Rename `tuning` to `query-tuning` and blacklist forcing explicit choice between this and `database-tuning`][5]
 - [Rename `sql` to `sql-language` and blacklist to prevent abuse][6]

---

 - [Make `sqlcmd-mode` a synonym of `sqlcmd`.][7] - **completed**
 - [Rename `sql-server-2011` to `sql-server-2012`. Make `denali` a synonym of `sql-server-2012`.][8] - **completed**
 - [Merge `locking` into `locks`][9] - **completed**
 - [Delete `xmltype`][10] - **completed**
 - [Delete `columns`][11] - **completed**  made synonym of [tag:database-design]
 - [Delete `add-column`][12] - **completed**
 - [Delete `data-migration`][13] - **completed**
 - [Delete `database`][14] - **completed**
 - [Merge `restore` and `recover`][15] - **declined**
 - [Delete `query-help`][16] - **completed**
 - [Rename `azure` to `sql-azure`][17] - **completed**
 - [Delete `mysql-replication`][18] - **completed**
 - [Delete `pg-restore`][19] - **completed**

**If you downvote a suggestion please explain why in a comment.**


  [1]: http://meta.dba.stackexchange.com/a/582/2660
  [2]: http://meta.dba.stackexchange.com/a/567/1396
  [3]: http://meta.dba.stackexchange.com/a/543/2660
  [4]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/409#409
  [5]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/483#483
  [6]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/484#484
  [7]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/474#474
  [8]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/456#456
  [9]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/453#453
  [10]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/435#435
  [11]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/410#410
  [12]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/406#406
  [13]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/388#388
  [14]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/392#392
  [15]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/386#386
  [16]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/385#385
  [17]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/384#384
  [18]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/383#383
  [19]: http://meta.dba.stackexchange.com/questions/382/tag-cleanup-vote-for-the-following-proposed-tag-changes/387#387
  [20]: http://meta.dba.stackexchange.com/a/615/1396