Improving an Alliance Capital

Introduction
Each sector capital has a unique bonus given, usually you need to be in that sector to gain the benefits. Example:

The more you upgrade the capital, the better the bonuses become.

How To
Select the capital → View → Elite Capital

You'll need to complete the tasks listed over a period of time and at the end, your capital will be upgraded.

When you select "Reestablish Order" you'll notice this icon on the right.

It means that in this sector you'll find "Plunderer" pirates that you need to destroy. These special pirates will be marked on the map with the icon below.