More than 20 choices for Multi-select drop down?

I don�t have a hack to allow more than 20 choices, but this can be set up as a proper Many to Many relationship where 1 contractor has many Contractor Country Assignments and 1Country has many Contractor Country Assignments. So you would need to add that middle �Join� table.

I do have a technique to let you add these quickly.

An alternative to your 20 limit would be to have two fields, but that is messy.