There is also a custom  permission for each limited item.
For Example:

If you want to give someone permission to override limits for SPONGE with DATA 1 (Wet sponge),
it will be 'nilimits.override.SPONGE:1' because of its name SPONGE and DATA 1.

     nilimits.add:
        description: Allows the player to add counted items.
        default: OP
    nilimits.view:
        description: Allows the player to view counted items.
        default: true
    nilimits.info:
        description: Allows the player to view region limits.
        default: true
    nilimits.override.*:
        description: Allows the player to override plugin limits.
        default: OP
    nilimits.reload:
        description: Allows the player to reload the plugin.
        default: OP