The IRS instructions for preparing W-2 forms state:

Code G—Elective deferrals and employer
contributions (including nonelective deferrals) to any
governmental or nongovernmental section 457(b)
deferred compensation plan.

Up until about 1986, here in Arizona, these were after-tax.  Since then, they are pre-tax and not shown in Box 1.  

What may be confusing is that the instructions also state:

The following are not elective deferrals and may be
reported in box 14, but not in box 12.
• Nonelective employer contributions made on behalf of
an employee

But the specific (government employees) applies over the general (everyone else).