- Added fields `reason` and `fieldPath` into CRD validation rules to allow users to specify reason and field path when validation failed. ([#118041](https://github.com/kubernetes/kubernetes/pull/118041), [@cici37](https://github.com/cici37)) [SIG API Machinery]

### Feature

- 'Added selector validation to `HorizontalPodAutoscaler`: when multiple HPAs
  select the same set of Pods, scaling now will be disabled for those HPAs with
  the reason `AmbiguousSelector`. This change also covers a case when multiple HPAs
  point to the same deployment.'
   ([#112011](https://github.com/kubernetes/kubernetes/pull/112011), [@pbeschetnov](https://github.com/pbeschetnov))

    /** The key of the configuration. e.g. ou=People,dc=fess,dc=codelibs,dc=org */
    String LDAP_ADMIN_USER_BASE_DN = "ldap.admin.user.base.dn";

    /** The key of the configuration. e.g. organizationalPerson,top,person,inetOrgPerson */
    String LDAP_ADMIN_USER_OBJECT_CLASSES = "ldap.admin.user.object.classes";

    /** The key of the configuration. e.g. cn=%s */
    String LDAP_ADMIN_ROLE_FILTER = "ldap.admin.role.filter";

- Add "reason" field to image_garbage_collected_total metric, so admins can differentiate images that were collected for reason "age" vs "space" ([#123345](https://github.com/kubernetes/kubernetes/pull/123345), [@haircommander](https://github.com/haircommander)) [SIG Node]

- **Apps**
  - [stable] When replica sets cannot create pods, they will now report detail via the API about the underlying reason ([kubernetes/features#120](https://github.com/kubernetes/enhancements/issues/120))

- Introduction of the `DisruptionTarget` pod condition type. Its `reason` field indicates the reason for pod termination:
  - PreemptionByKubeScheduler (Pod preempted by kube-scheduler)
  - DeletionByTaintManager (Pod deleted by taint manager due to NoExecute taint)

1F9CB         ; valid                  ;      ; NV8    # 13.0 BUBBLE TEA
1F9CC         ; valid                  ;      ; NV8    # 14.0 TROLL
1F9CD..1F9CF  ; valid                  ;      ; NV8    # 12.0 STANDING PERSON..DEAF PERSON
1F9D0..1F9E6  ; valid                  ;      ; NV8    # 10.0 FACE WITH MONOCLE..SOCKS
1F9E7..1F9FF  ; valid                  ;      ; NV8    # 11.0 RED GIFT ENVELOPE..NAZAR AMULET

- If scheduling fails on PreBind or Bind, scheduler will retry the failed pod immediately after backoff time, regardless of the reason for failing. In this case EventsToRegister (QHints) will not be taken into consideration before retry. ([#130189](https://github.com/kubernetes/kubernetes/pull/130189), [@ania-borowiec](https://github.com/ania-borowiec)) [SIG Scheduling]

### Documentation

- Documented the reason field in CRI API to ensure it equals `OOMKilled` for the containers terminated by OOM killer ([#112977](https://github.com/kubernetes/kubernetes/pull/112977), [@mimowo](https://github.com/mimowo))

- Append the image pull error for the pods `status.containerStatuses[*].state.waiting.message` when
  in image pull back-off (`reason` is `ImagePullBackOff`) instead of the generic `Back-off pulling image…` message. ([#127918](https://github.com/kubernetes/kubernetes/pull/127918), [@saschagrunert](https://github.com/saschagrunert)) [SIG Node and Testing]