Oregon allows Full year residents to claim a credit on an Oregon state tax return for tax paid on the same income taxed by any other state than Arizona, California, Indiana, or Virginia.
Nonresidents may claim a credit on an Oregon return if you paid taxes on the same income to both Oregon AND one of the four states Arizona, California, Indiana, or Virginia.
That is why you are only seeing 4 states in this view.
Oregon Individual Income Tax Guide (see pg 96 and 97, 2nd column)
