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
15339	Please document the behaviour of RelatedManager when the same object is added twice	jammon	nobody	"As I understand the code in `django.db.models.fields.related` the `_add_items` method of `ManyRelatedManager` takes care that the same object isn't added twice.

So I suggest to document that in `/ref/models/relations/#django.db.models.fields.related.RelatedManager.add`, maybe like this: ""Adding a model that is already in the related object set has no effect, it won't be contained twice afterwards.""

(I looked it up in the code, but just a year ago that would have been difficult for me.)"	Bug	closed	Documentation	1.3-beta	Normal	wontfix			Accepted	0	0	0	0	0	0