== Background
We are planning on deploying the new language switching functionality. We will begin with logged-in users that have opted our of legacy vector
== Acceptance criteria
[] Stage 1: deploy to testwiki and officewiki
- Ensure full QA has been completed on these wikis
[] Stage 2: Deploy new language switching functionality to all users that have opted out of legacy vector
* **Exclude** the following pilot wikis from the above:
Basque Wikipedia
French Wikipedia
French Wiktionary
Hebrew Wikipedia
Persian Wikipedia
Portuguese Wikiversity
Bengali Wikipedia
German Wikivoyage
Korean Wikipedia
Portuguese Wikipedia
Serbian Wikipedia
Turkish Wikipedia
Venetian Wikipedia
Wikimedia Incubator
# Developer notes
Required config change is:
```
$wgVectorLanguageInHeader" = [
"logged_in" => true
"logged_out"=> false
];```