PA Local Taxable Wages and 401K

[payrolltax 24]

Hello, we have quite a few employees working in Pennsylvania Remote/In office. We are aware of a few Localities that include 401K contributions in local taxable wages, however one employee is questioning her specific local of West Chester Boro. I cannot find any information that states that locality should include 401K in taxable wages. I contacted Keystone who collects the local taxes for that specific local but they said they could not provide tax advice, which that is not tax advice that is a valid Tax Question for the Tax collector. I've also contacted ADP who files on our behalf and they did not have any information. Does anyone have a list of PA Locals that tax 401K contributions and those that don't? Or can someone let me know if West Chester Boro should include 401K in taxable wages?

[BillM223]

I cannot answer your immediate question on which localities do or don't include 401(k) contributions in taxable income.

But while researching this, I have come to wonder the following:

Since 401(k) contributions are not excluded from state income in Pennsylvania, I would assume that all localities include the 401(k) contributions in taxable income. 

What locality does not include 40(k) contributions in taxable income, and where do they say this?