List Fields can be used to aid resolving of replication or save conflicts. If a replication or save conflict occur, you will often see them as so-called diamond rows (due to the black diamond icon at the very left) with the text Replication or Save conflict. Below you see such a document in a view
If you have multiple replication or save conflicts, they may look like this:
Some databases may also contain special views displaying only replication conflicts, in order to keep the other main views clear from conflict documents. The screenshot above has grouped the replication conflicts after their Notes Form-name, and thus you don't see all participants in the conflict.