Deprecation: #83905 - TypoScriptFrontendController->page_cache_reg1¶
TypoScriptFrontendController->page_cache_reg1 has been marked as deprecated.
Setting this property triggers a deprecation warning.
This property was of very little use ever since, it is unlikely an instance runs an extension consuming it. The extension scanner will find usages.
TypoScriptFrontendController->addCacheTags() to influence page cache tagging.