Generally speaking, the higher the reputation with a Faction, the more they like <player>. Conversely, the lower the reputation, the more <player>'s disliked. Good reputation leads to (more, higher-paying) missions, improved trading discounts & the availability of Licenses in the more lawful systems of Albion and Omicron Lyrae (resulting in increased mission variety, rewards and cash bonuses for shooting hostiles), and not getting shot in the face.

 

Reputation
level
Relation
value 
Reputation
title 
Faction colourDiscount on
station wares
NPC discount &
commission
Other notes
+301 Blue*25%20%*<Player> faction always displayed in green; permanent +30 rep
+27  Blue  100% info unlocked for all the faction's stations
+25  Blue  Argon Secret Service
(Secret Service chain mission reward licence requirement)
+20  Blue???%15%Plutarch Defence Initiative Membership;
HoA Defence Membership;
Argon Navy Membership 
+10  

Blue 

???% 5% Police Licence;
Intoxicants License;
Pharmaceuticals Licence 
+5  Blue -Protected Species Licence;
Hazardous Materials Licence
00 Blue --
-4 (?)  Blue --
-5 (?) to -16  Red Docking, Trade and Mission access suspended;
Otani's ships and stations with aggressive orders will attack faction;
Otani's capitals with Defense Officers set to Attack will start fights
-17 and below  RedOtani and his FIGHT ships will be attacked at all times
-18 and below (min -30)  Red--

All Otani's property will be attacked at all times