REF ON i-485, Please shed light

I just received a REF on my I-485 (EB2 NIW, PD MARCH 2007), which says :

Please submit a currently dated letter of employment and other documentary evidence, which established that you will continue to be engaged in the occupation of which the national interest waiver is base.

This evidence shall specify how you intend to serve the national interest and confirm that you intend to carry out the terms and conditions of the underlying I-140 petition.

Does the the second half mean a job description or something?

Appreciate any comments!