Like the deployment checklist T411065, but in reverse.
**Reason**
Archiving the WP25EasterEggs extension following the end of the Wikipedia 25th anniversary celebration.
---
## Undeployment Checklist
### This Task
- [x] Add maintainers of WP25EasterEggs as subscribers to this task (if they have no apparent Phabricator account, notify them on-wiki or via email if possible and note it here).
- [x] Add Phabricator project #mediawiki-extensions-wp25eastereggs as a tag for this task
### On-Wiki Documentation
- [ ] Archive extension page https://www.mediawiki.org/wiki/Extension:WP25EasterEggs: replace page contents with `{{Archived extension|last revision id before archiving|task=T######}}`.
- [ ] If documentation page was translatable, remove `<translate>`, visit Special:PageTranslation, and click "remove from translation" (if you don't have the translation administrator right, ask a [[ https://www.mediawiki.org/wiki/Special:ListUsers/translationadmin | user who does ]]).
- [ ] Archive the help page https://www.mediawiki.org/wiki/Help:Extension:WP25EasterEggs
- [ ] WMF stewardship: Remove the project from the mediawiki Maintainers page
- [ ] Update Wikidata item associated with documentation page:
- [ ] Add statement `Abandonware (Q281039)` to `instance of (P31)` together with qualifier `start time (P580)` = YYYY-MM-DD date of archival
- [ ] Add qualifier `end time (P582)` = YYYY-MM-DD (same date) to `instance of (P31) = MediaWiki extension (Q6805426)`
### Phabricator
- [ ] Mark all Phabricator tasks for the extension either Declined or Invalid. Add a comment pointing to this task when doing so for reference.
- [ ] Archive Phabricator project #mediawiki-extensions-wp25eastereggs
- [ ] Archive Phabricator project #pes1.3.3_wp25_easter_eggs
- [ ] Edit Phabricator project descriptions with a link to this ticket.
### Code (Listed in Operational Order)
- [ ] Disable the feature flag in wikimedia-config
- [ ] Remove the extension from the production branch in mediawiki-config
- [ ] Revert changes made in Vector to support baby globe
- [ ] Revert changes made in MobileFrontend to support baby globe
### Portal
- [ ] Remove the birthday mode features from www.wikipedia.org
### Translatewiki.net / Translations
- [ ] Remove the extension completely from translatewiki.net by ensuring its project IDs don't appear in any of the following files:
- [ ] [[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/groups/MediaWiki/ExtensionsAgg.yaml | groups/MediaWiki/ExtensionsAgg.yaml ]]
- [ ] [[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/groups/MediaWiki/mediawiki-extensions.txt | groups/MediaWiki/mediawiki-extensions.txt ]]
- [ ] [[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/repoconfig.yaml | repoconfig.yaml ]]
- [ ] [[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/mw-config/validation-exclusion-list.php | mw-config/validation-exclusion-list.php ]]
- [ ] Remove from WikimediaMainAgg.yaml, WikimediaAdvancedAgg.yaml, WikimediaLegacyAgg.yaml, or WikimediaTechnicalAgg.yaml as applicable.
### Configuration / Tests / Integrations
- [ ] Remove tests in [[ https://gerrit.wikimedia.org/g/integration/config | integration/config ]] ([[ https://gerrit.wikimedia.org/r/plugins/gitiles/integration/config/+/master/zuul/layout.yaml | zuul/layout.yaml ]]).
- [ ] Remove manifest/other references from [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/vagrant/+/master | mediawiki/vagrant ]] if they exist.
- [ ] Remove from https://doc.wikimedia.org/cover-extensions/ if present (requires #continuous-integration-infrastructure shell user to delete directly from the server).
### Repositories
- [ ] Remove from [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/+/master | mediawiki/extensions ]] (along with in `.gitmodules`).
- [ ] Mark the repository read-only in Gerrit: edit description to prepend "[ARCHIVED]" and a reference to this task, remove all access lists and reparent on `All-Archived-Projects`: (provide Gerrit Repository URL).
- [ ] Deactivate the Diffusion repository for the extension: (provide the Diffusion repository callsign or URL).
- [ ] Delete the GitHub mirror: (provide GitHub repository URL).