- binary-search-tree should be used to refer to questions specific to BSTs (not binary trees in general)
- binary-tree should be used to refer to non-BST binary trees.
- tree should be used to refer to non-binary trees.
- binary should not be used to refer to binary trees at all.
- All BSTs are binary trees, so tagging a question with both binary-search-tree and binary-tree or tree is redundant.
- Similarly, all binary trees are trees, thus using both binary-tree and tree is redundant.
- binary currently refers to binary numbers, it should not be used for binary trees as well.
- [binary] which refers to trees x225
- [tree] which refers to BSTs x343
- [tree] which refers to binary trees x538
- [binary-tree] which refers to BSTs x599
- [binary-tree] and [tree] x219
- [binary-search-tree] and [tree] x107
- [binary-search-tree] and [binary-tree] x160
(there's probably a bit of overlap in the above searches and they may not be 100% exact)
Not all of the questions in these results are necessarily bad - some questions may ask about both binary trees and trees in general, or about differences between the different types.
Note that because the question is asking about a BST doesn't mean it's specific to a BST - finding the depth of a BST is the same as finding the depth of regular binary tree, thus binary-tree should be used there, not binary-search-tree.
And there are plenty of questions that say binary tree (and probably many that are also tagged as such) but actually mean BST.
There issue is likely to creep up again. It might be wise to put a note in each of the tag excerpts. And perhaps rename tree (any suggestions?).
I've already done a fair amount of retagging with regard to this.