vBulletin Manual - Post Icon Mass Move

Selecting the Mass Move option will display all the Post Icons from the selected category.

Each Post Icon has a drop down menu containing all the other available categories. You can opt to move some or all the Post Icons in the selected category and you can move different Post Icons to different categories in one action.

You can specify the category for each individual Post Icon, or if all the Post Icons are moving to the same category there is a separate global menu for you to select the category from.