When I send an email. There is the to: which can be the main sub. And then the cc: the sub tagged that aou wants it in or if some other guy likes the post and wants to have it show up in their sub. They can add their tag... So if people are posting to funny. And I got my sub that's called "memes that can red pill my boomer dad while he eats his shreddies cereal" I can keep the comments rolling aaaaand I a copy of it in my own sub. It avoids duplicate postings. 🤷🏻‍♂️ answer might be obvious but my iq is 14.