Old cat, could help read this legal document

Hi, Old Cat:

The following is cited from a formal document.
"If your form I-485 is related to an employment-based visa petition (Form I-140), you must submit a letter on the letterhead of the petitioning employer which confirms that the job on which the visa petition is based is still available to you. The letter must also state the salary that will be paid"

My Form I-140 (EB1A) petition is not employment-based. So the above is not applicable to my case, that is, the employment letter is not necessary, I think. Do you agree?

In the Immigration 论坛, I asked, no professional advice. So hope you can help.