@TaxGuyBill Not sure where you are reading, but the 2024 instructions state as follows:

Only elective deferrals and designated Roth contributions should be reported in box 12 for all coded plans; except, when using code G for section 457(b) plans, include both elective and nonelective deferrals.

Here is the link for the 2024 instructions.

https://www.irs.gov/instructions/iw2w3