Retirement tax questions
According to this State of Pennsylvania source, distributions from nonqualified pension sources is taxable income and is not treated as an tax-exempt plan.
If you feel that this doesn't apply to you, you may leave Box 11 blank if it isn't a distribution taken from a non-qualified plan or a non-qualified 457 plan.
For your reference, I've included a screenshot from a on-demand tax guidance from TurboTax that states this.
