* `--feature-gates` argument has been removed from the `kubeadm join` command. Feature gates will be retrieved from the cluster configuration during the join process. ([#70755](https://github.com/kubernetes/kubernetes/pull/70755), [@ereslibre](https://github.com/ereslibre))

- The `kubeadm join` command can now be used in phases. Similar to the work that was done for `kubeadm init` in 1.13, in 1.14 the `join` phases can be now executed step-by-step/selectively using the `kubeadm join phase` sub-command. This makes it possible to further customize the workflow of joining nodes to the cluster.
kubernetes/kubeadm: [#1204](https://github.com/kubernetes/kubeadm/issues/1204)

flag `--experimental-patches` is now deprecated and will be removed in a future release. You can migrate to using the new flag `--patches`. Add a new field `{Init|Join}Configuration.patches.directory` that can be used for the same purpose. For `init` and `join` it is now recommended that you migrate to configure patches via `{Init|Join}Configuration.patches.directory`. For the time being, these flags can be mixed with `--config`, but that might change in the future. On a command line, the last *patches...

* kubeadm: Fix a bug where if couple of CRIs are installed a user override of the CRI during join (via kubeadm join --cri-socket ...) is ignored and kubeadm bails out with an error ([#76505](https://github.com/kubernetes/kubernetes/pull/76505), [@rosti](https://github.com/rosti))

* kubeadm: Fix a bug where `kubeadm join` would wait 5 seconds without doing anything. Now `kubeadm join` executes the tasks immediately. ([#48737](https://github.com/kubernetes/kubernetes/pull/48737), [@mattmoyer](https://github.com/mattmoyer))

- Kubeadm: fix a whitespace issue in the output of the "kubeadm join" command shown as the output of "kubeadm init" and "kubeadm token create --print-join-command" ([#97413](https://github.com/kubernetes/kubernetes/pull/97413), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- Kubeadm: during join when a check is performed that a Node with the same name already exists in the cluster, make sure the NodeReady condition is properly validated ([#89602](https://github.com/kubernetes/kubernetes/pull/89602), [@kvaps](https://github.com/kvaps)) [SIG Cluster Lifecycle]

 `--token-ttl 0` to `kubeadm init`. The default token can later be deleted with
 `kubeadm token delete`.

 - `kubeadm join` now delegates TLS Bootstrapping to the kubelet itself, instead
 of reimplementing the process. `kubeadm join` writes the bootstrap kubeconfig
 file to `/etc/kubernetes/bootstrap-kubelet.conf`.

#### Defaults

- Kubeadm: added `show-join-command` as a new separate phase at the end of `kubeadm init`. You can skip printing the join information by using `kubeadm init --skip-phases=show-join-command`. Executing only this phase on demand will throw an error because the phase needs dependencies such as bootstrap tokens to be pre-populated. ([#111512](https://git...

### (No, really, you MUST read this before you upgrade)

- Kubeadm: remove the deprecated flag `--experimental-patches` for the `init|join|upgrade` commands. The flag `--patches` is no longer allowed in a mixture with the flag `--config`. Please use the kubeadm configuration for setting patches for a node using `{Init|Join}Configuration.patches`. ([#104065](https://github.com/kubernetes/kubernetes/pull/104065), [@pacoxu](https://github.com/pacoxu))