turbo tax says, box 14, you just input whatever in

item box 14 on W2. I just do the numbers in Turbo tax and later print out and mail them to IRS, not efiling.

I googled and it seems SDI is mandatory and VPDI is voluntary, and to my understanding, only mandatory can be deductible? But how come the other company has no SDI, isn't it mandatory to all California companies?Here is the what I found:

What is State Disability Insurance (SDI)?
State Disability Insurance (SDI) is a state tax assessed on an employee's wages. The tax goes into a fund, maintained by the Employment Development Department, which is used to pay disability benefits.
SDI is paid by the employee and is withheld from the employee's wages by the employer. (If the employer pays the SDI tax, the employer must include the benefit in the employee’s wages. Thus, the employee is still considered to have paid the SDI.)
The amount of SDI withheld is shown on the Form W-2. Generally, it’s reported in the "local income tax" box.
What is Voluntary Plan Disability Insurance (VPDI)?
Voluntary Plan Disability Insurance (VPDI) is a private disability insurance plan which meets the requirements of, and is approved by the State of California.
The amount of VPDI withheld is shown as "VPDI" on the Form W-2.