optional bool watch = 3;

  // allowWatchBookmarks requests watch events with type "BOOKMARK".
  // Servers that do not implement bookmarks may ignore this flag and
  // bookmarks are sent at the server's discretion. Clients should not
  // assume bookmarks are returned at any specific interval, nor may they
  // assume the server will send any BOOKMARK event during a session.
  // If this is not a watch, this field is ignored.
  // +optional

- The synthetic "Bookmark" event for the watch stream requests will now include a new annotation: `kubernetes.io/initial-events-list-blueprint`. THe annotation contains an empty, versioned list that is encoded in the requested format (such as protobuf, JSON, or CBOR), then...

- Implemented API streaming for the `watch-cache`
  
  When `sendInitialEvents` `ListOption` is set together with `watch=true`, it begins the watch stream with synthetic init events followed by a synthetic "Bookmark" after which the server continues streaming events. ([#110960](https://github.com/kubernetes/kubernetes/pull/110960), [@p0lyn0mial](https://github.com/p0lyn0mial))
- Introduced API for streaming.
  

- Implemented API for streaming for the `etcd` store implementation.
  When `sendInitialEvents ListOption` is set together with `watch=true`, it begins the watch stream with synthetic init events followed by a synthetic `Bookmark`, after which the server continues streaming events. ([#119557](https://github.com/kubernetes/kubernetes/pull/119557), [@p0lyn0mial](https://github.com/p0lyn0mial))

- Client-go/reflector: warns when the bookmark event for initial events hasn't been received ([#124614](https://github.com/kubernetes/kubernetes/pull/124614), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery]

* Introduce API for watch bookmark events. ([#74074](https://github.com/kubernetes/kubernetes/pull/74074), [@wojtek-t](https://github.com/wojtek-t))
    * Introduce Alpha field `AllowWatchBookmarks` in ListOptions for requesting watch bookmarks from apiserver. The implementation in apiserver is hidden behind feature gate `WatchBookmark` (currently in Alpha stage).

- Try to send watch bookmarks (if requested) periodically in addition to sending them right before timeout ([#90560](https://github.com/kubernetes/kubernetes/pull/90560), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery]