Many alliances have rules of engagement for engaging (often referred to as RoE) in combat against other players (PvP play). On some servers (including this one), several of the larger and more powerful alliances will agree to a common set of rules. In addition, they insist that other alliances and solo players play according to their rules of engagement, and try to enforce it by declaring war and/or issuing "Kill on Sight" (KoS) orders against "rogue" alliances or individual players.
Most, but not all, of the common Rules of Engagement involve mining. The common RoE for this server are:
1. Survey ships (miners) can be attacked when carrying unprotected cargo (OPC), but not if their cargo is protected.
2. Survey ships can be attacked if they are not moved when a node has been completely depleted (0 node).
3. All other classes of ships (Battleships, Interceptors, and Explorers) may be attacked at any time, including while mining, regardless of the amount of cargo.
Additional rules may be added for more advanced parts of the game, but these are the basics.
Each ship can carry a different amount of protected cargo, depending on class and upgrades. To see how much your ship can protect, highlight the ship in the drydock area at the bottom of the screen.
Then select "MANAGE".
Then tap to change from the MAIN STATS tab to the DETAILS tab.
Scroll down to the UTILITY section and it will show the cargo capacity and the protected cargo.
Protected cargo means you can't lose it, even if your ship is destroyed. If another player attacks your ship and destroys it, the amount of protected cargo is deposited safely in your station. The rest, the unprotected cargo, goes the the attacker.