Pillagers wear the Illager Banner on their chest slot

The Illager Banner is worn on the chest slot of the pillagers. This can be confirmed if you do the following:

• Dispense full armor on a pillager (Chestplate will not be equipped and it shows that the pillagers can wear helmets with the banner.)
• Or using the command which removes the banner.

  /replaceitem entity @e[type=pillager] slot.armor.chest 1 air 

   Attachments were made before 1.13.0.5.