DS - 157 : Required ?

[05skp12]

Is DS-157 required to get parents ? I thought it was only required for male applicants between 16 and 45 yrs of age. In the instruction form which we received after taking an apptmt over web, it says DS-157 has to be filled for all applicants.
Please clarify

[immihelp]

Read https://www.immihelp.com/usa-visas/visitor