Both were added as part of the initial implementation in commit [moby@ea30113]
([libnetwork@1d6f2c5]), but never used.
[moby@ea30113]: https://github.com/moby/moby/commit/ea301133039d9852455893a4ada1ab887ebe8459
[libnetwork@1d6f2c5]: https://github.com/moby/libnetwork/commit/1d6f2c59c46fa6533d8cbf3d648f001a5da7c19c
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>