We are currently serializing and storing objects in the cache for BannerMessageGroup.
BannerMessageGroup is currently serialized as:
O:18:"BannerMessageGroup":11:{s:13:"^@*^@bannerName";s:24:"Genericmaintenancenotice";s:12:"^@*^@namespace";i:866;s:9:"^@*^@source";N;s:8:"^@*^@label";s:57:"MediaWiki:Centralnotice-template-Genericmaintenancenotice";s:5:"^@*^@id";s:45:"Centralnotice-tgroup-Genericmaintenancenotice";s:11:"^@*^@optional";a:0:{}s:10:"^@*^@ignored";a:0:{}s:14:"^@*^@description";N;s:7:"^@*^@meta";b:0;s:10:"^@*^@mangler";N;s:11:"^@*^@messages";a:0:{}}s:34:"Centralnotice-tgroup-newtestbanner";Compare this with wikipage serialization:
i:52;s:30:"Category:Wikimedia Deutschland"