Here is a small tip for Android Studio. I added a bookmark by accident, in one of my source file, and I did not find out easily how to remove it.
How to add or remove Android Studio bookmarks
Go to Navigate > Bookmarks > Toggle Bookmark or press F11 (Windows) or f3 (Mac OS). In this menu you can also display a list of your current bookmarks.
You can also add or remove bookmarks with numbers (Mnemonic Bookmarks). It is useful if you want to jump to a specific bookmark : just press CTRL+number of your bookmark.
Note: last known version of Android Studio in which this works is 188.8.131.52
Hope it will help you!