I have 2 issues with constraints in Oracle 9i that I can't find out how to do.

1. Middle initial must be null, blank, or capital-A through capital-Z

2. INV_SIZE must be null, blank, a one or two digit number, S, M, L, XS, XL, XXS, XXL, 3XS, 3XL, 4XS, 4XL, 9XS, 9XL

What would be the best way to put these constraints on my columns?

Thank you for your help!!