id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
18211	Add a signal to notifying when a ModelAdmin has been registered with an AdminSite	filip.dupanovic@…	nobody	"When your trying to unregister a ModelAdmin instance from a particular AdminSite, it's possible that at the point of time the statement is being executed the ModelAdmin hasn't been registered and you'll get an unhandled exception.

The only way to resolve this is to rearrange the `INSTALLED_APPS` to make sure the particular application's modules are being imported after the ModelAdmin has been registered. If we can latch onto a signal that will notify us when a site instance has had a ModelAdmin registered, we'd have a more elegant approach to unregistering model administration we don't want to appear on the admin site."	New feature	closed	contrib.admin		Normal	wontfix			Unreviewed	0	0	0	0	0	0