Welcome back Siberian.

Go to the link that SOGFPP provided and go down to where it says:
[b:2i7hexwc]”Sharing Sacramental Life with Christians of Other Churches and Ecclesial Communities”[/b:2i7hexwc]

It explains it there for you.
Although you may have an imperfect communion with the Catholic Church at the moment. I personally think you should of waited until you understood and believed.

~Victor