How to: Does Powerlevel10k always render exactly the same prompt as Powerlevel9k given the same config?
Almost. There are a few differences.

- By default only `git` vcs backend is enabled in Powerlevel10k. If you need `svn` and `hg`, add
  them to `POWERLEVEL9K_VCS_BACKENDS`. These backends aren't yet optimized in Powerlevel10k, so
  enabling them will make prompt *very slow*.
- Powerlevel10k doesn't support `POWERLEVEL9K_VCS_SHOW_SUBMODULE_DIRTY=true`.
- Powerlevel10k strives to be bug-compatible with Powerlevel9k but not when it comes to egregious
  bugs. If you accidentally rely on these bugs, your prompt will differ between Powerlevel9k and
  Powerlevel10k. Some examples:
  - Powerlevel9k ignores some options that are set after the theme is sourced while Powerlevel10k
    respects all options. If you see different icons in Powerlevel9k and Powerlevel10k, you've
    probably defined `POWERLEVEL9K_MODE` before sourcing the theme. This parameter gets ignored
    by Powerlevel9k but honored by Powerlevel10k. If you want your prompt to look in Powerlevel10k
    the same as in Powerlevel9k, remove `POWERLEVEL9K_MODE`.
  - Powerlevel9k doesn't respect `ZLE_RPROMPT_INDENT`. As a result, right prompt in Powerlevel10k
    can have an extra space at the end compared to Powerlevel9k. Set `ZLE_RPROMPT_INDENT=0` if you
    don't want that space. More details in
    [troubleshooting](#extra-space-without-background-on-the-right-side-of-right-prompt).
  - Powerlevel9k has inconsistent spacing around icons. This was fixed in Powerlevel10k. Set
    `POWERLEVEL9K_LEGACY_ICON_SPACING=true` to get the same spacing as in Powerlevel9k.  More
    details in [troubleshooting](#extra-or-missing-spaces-around-icons).
  - There are dozens more bugs in Powerlevel9k that don't exist in Powerlevel10k.

If you notice any other changes in prompt appearance when switching from Powerlevel9k to
Powerlevel10k, please [open an issue](https://github.com/romkatv/powerlevel10k/issues).