Tax Year 2015: Congress approved a cash rebate in December of 2015. What is the name and number of the IRS form?

Unfortunately, there is no cash rebate and no separate form to claim one.  What happened is that certain laws that were "temporary" were made permanent.  

I can't really post an outside link to unverified websites. However, if you search the internet enough, you will find that there is no truth to a cash rebate being available for taxes.

Thank you.  I thought it was too good to be true.

You're welcome.  It is sad that there are individuals out there who misrepresent.  Best wishes.

The legislation is titled “Protecting Americans From Tax Hikes Act of 2015” or, informally, the PATH Act.
Passed in December 2015.  Partly refers to Sales Tax Deduction vs. State Income Tax Deduction.  IRS has a calculator online for figuring which would be to your advantage.  The greater can be deducted on Schedule A.

That would be a deduction on Schedule A, as you said.  Also, the TurboTax software calculates that as well.

Thank you, why don't these people get sued?  The only wealth they same to be expanding is their own if you get conned into joining their club.

The legislation is titled “Protecting Americans From Tax Hikes Act of 2015” or, informally, the PATH Act.
Passed in December 2015.  Partly refers to Sales Tax Deduction vs. State Income Tax Deduction.  IRS has a calculator online for figuring which would be to your advantage.  The greater can be deducted on Schedule A.