Linking a pull request to an issue
To link a pull request to an issue to show that a fix is in progress and to automatically close the issue when someone merges the pull request, type one of the following keywords followed by a reference to the issue. For example,
Closes #10 or
For more information, see "Linking a pull request to an issue."
Marking an issue or pull request as a duplicate
To mark an issue or pull request as a duplicate, type "Duplicate of" followed by the issue or pull request number it duplicates in the body of a new comment. For more information, see "Marking issues or pull requests as a duplicate."