Feature prestige

Feature Prestige is a way to level up certain features past their maximum level, but at an increased cost. It requires at least 1M total sectors cleared to be unlocked ~(unconfirmed). The currency that is used to increase a features' max level is called Prestige Points (PP). 1 PP is received for every 1M total sectors cleared. The only method of reducing the amount of sectors needed to clear is currently only by getting the sentinel protocol 'Prestige Protocol', which cost 250 SP and requires SL 15.

Once unlocked, it can be accessed by clicking the vaguely gear shaped image with a circle in the middle. There it, will tell you of all sorts of information. The top bar tells you how many available / total PP you have, and also the amount of sectors you need to clear before receiving the next PP. The list of features displayed are the ones that can prestige, as well as how much the maximum level gets increased by, how much the price will be multiplied by by, the current prestige level and the cost to increase the prestige level.

For now, there is no known method to reset used Prestige Points.

Source: link (created by Hiroko)

You can also view the table with more information as editable Google Spreadsheet (created by Xyrtion).