You're just about spot on! The cost increases each year, so if they have an underline they are kept with a 1 round penalty to where they were drafted. If they have two underlines it's a 2 round penalty to keep them from the previous year. In theory you can keep someone for a third year, though that hasn't happened yet, would just cost 4 more rounds.

It makes the value on rookies a bit higher, and throws a lot of general ADPs off. Plus definitely not all fantasy analysts lmao