![](https://reddthat.com/pictrs/image/ece537cd-6907-4b95-8779-17dcbf4871c2.jpeg)
![](https://lemmy.world/pictrs/image/44bf11eb-4336-40eb-9778-e96fc5223124.png)
Lemmy aggregates all posts with the same links as crossposts. In fact, you don’t have to use the crosspost function, but it adds a link to the main post in the description which is cool. It gives you more awareness that it’s a duplicated post and can link to a community that is not federated and thus doesn’t display as a crosspost.
edit: I guess posts without a linked article, video or photo are not displayed as crossposts. In that case, there is nothing left to do but to add information in the post that this is a crosspost and add a link to the original.
It will if the links are the same, but people often upload the same meme or other graphics on different instances as a result there are different links and posts are not detected as crossposts. I know because I used to do it myself. It is best to use the crosspost button. It’s always nice to make sure there’s a link to the original post in the description, because some people may not see crossposts if they’re not federated with the community.