Best practices relational design
These look, to me, like statuses in a workflow that you are creating.
As such, it is highly likely that these status values will change over time.  Because of this, I would discount the use of an Enum.  Changing an Enum requires you to change the table definition, which requires you (as DBA) to get involved.  Adding a new status [row] into a regular table makes it very easy to add new statuses, potentially even being a part of your application and Users being able to do this for themselves!  (Obviously, you'll have a constraint that prevents them from deleting statuses that are in use!)

Also, I would recommend this approach over using a simple, varchar column, if only for the sake of consistency.  is it possible that someone (you?) could accidentally(?) enter a status of "WIP" instead of "wip" and what effect would that have on your application code?