I found two similar tags for referring to the "close, minimize, and maximize buttons".

* [tag:window-buttons] with 106 posts (6 asked this year), and
* [tag:window-control] with 7 posts (1 asked this year).

For clarification, I looked up at several sources:

* Wikipedia has [this relevant article][1] and apparently, the buttons are simply called "titlebar buttons" or "buttons" with given context.
* User Experience SE seems to agree with Wikipedia, in which there is no specific tag and searching with [is:questions window button][2] will return questions tagged with "buttons" and "window" separately.
* Qt GUI documentation seems to agree with both Wikipedia and User Experience SE, although the term "button" is almost never used for explaining the QWindow Class but nevertheless "titlebar buttons" is mentioned once under [the windowState() const][3].

Hence the tag synonyms suggestions:

* [tag:window-buttons] is most used and should be the parent tag
* [tag:window-control] is least used should be suggested as [tag synonyms of the parent][this]
* [tag:titlebar-buttons] is not used, but may be created and suggested as [tag synonyms as well][this]

The parent tag has no synonyms yet, and I do not have sufficient scores to suggest synonyms. I hope other users with priviledge can help to suggest synonyms as described and to retag the 7 posts with the parent tag as well. Um, I think that is all about the tag synonyms suggestion?


[1]: https://en.wikipedia.org/wiki/Window_decoration
[2]: https://ux.stackexchange.com/search?q=is%3Aquestion+window+button
[3]: https://doc.qt.io/qt-5/qwindow.html#windowState
[this]: https://askubuntu.com/tags/window-buttons/synonyms