I think this is all the additional modules and modifications that have been published over the years, not including the Star Nations from Hotel Nebula California. Did I miss any?
Affiliation: Principality of Rasalhague (Age of War) Era Digest: Age of War p. 19
Affiliation: Major Periphery State: Rim Worlds Republic (Age of War) Era Digest: Age of War p. 19
Affiliation: Capellan Confederation (Star League) Era Report: 2750, p. 150
Affiliation: Draconis Combine (Star League) Era Report: 2750, pp. 150-151
Affiliation: Federated Suns (Star League) Era Report: 2750, p. 151
Affiliation: Free Worlds League (Star League) Era Report: 2750, p. 151
Affiliation: Lyran Commonwealth (Star League) Era Report: 2750, pp. 151-152
Affiliation: Terran Hegemony (Star League) Era Report: 2750, pp. 152-153
Affiliation: Rim Worlds Republic (Star League) Era Report: 2750, p. 153
Affiliation: Other Periphery States (Star League) Era Report: 2750, p. 153
Stage 1: Born Mercenary Brat (Star League) Era Report: 2750, p. 154
Stage 1: Slave (Star League) Era Report: 2750, p. 154
Stage 1: War Orphan (Star League) Era Report: 2750, p. 154
Stage 2: Mercenary Brat (Star League) Era Report: 2750, p. 154
Stage 3: Land-Air ’Mech Training (Star League) Era Report: 2750, p. 154
Stage 4: Tour of Duty (Star League) Era Report: 2750, p. 154
Stage 4: Department of Mega-Engineering (Star League) Era Report: 2750, p. 154
Phenotype (MechWarrior, Aerospace) Era Digest: Golden Century p. 17
Phenotype (MechWarrior, Aerospace, Elemental after 2868 CHH CW) Era Digest: Golden Century p. 17
Phenotype (MechWarrior, Aerospace, Elemental) Era Digest: Golden Century p. 17
Affiliation: Homeworld Clan (Golden Century) Era Digest: Golden Century pp. 18-19
Affiliation: Minor Periphery: Aurigan Reach (Succession War) House Arano, p. 60
Affiliation: Capellan Confederation (Early Clan Invasion) Era Report: 3052, p. 158
Affiliation: Draconis Combine (Early Clan Invasion) Era Report: 3052, p. 158
Affiliation: Federated Commonwealth (Early Clan Invasion) Era Report: 3052, pp. 158-189
Affiliation: Free Rasalhague Republic (Early Clan Invasion) Era Report: 3052, p. 159
Affiliation: Major Periphery (Early Clan Invasion) Era Report: 3052, pp. 159-160
Affiliation: The Clans (Early Clan Invasion) Era Report: 3052, p. 160
Affiliation: ComStar (Early Clan Invasion) Era Report: 3052, p. 161
Affiliation: Capellan Confederation (Late Clan Invasion) Era Report: 3062, p. 152
Affiliation: Draconis Combine (Late Clan Invasion) Era Report: 3062, p. 152
Affiliation: Federated Commonwealth (Late Clan Invasion) Era Report: 3062, p. 153
Affiliation: Free Rasalhague Republic (Late Clan Invasion) Era Report: 3062, p. 153
Affiliation: Major Periphery State (Late Clan Invasion) Era Report: 3062, pp. 153-154
Affiliation: The Clans (Late Clan Invasion) Era Report: 3062, pp. 154-155
Affiliation: ComStar/Word of Blake (Late Clan Invasion) Era Report: 3062, p. 155
Affiliation: Second Star League (Late Clan Invasion) Era Report: 3062, p. 155
Affiliation: Capellan Confederation (Post-Jihad) Field Manual: 3085, p. 233
Affiliation: Draconis Combine (Post-Jihad) Field Manual: 3085, p. 233
Affiliation: Federated Suns (Post-Jihad) Field Manual: 3085, p. 233
Affiliation: Former Free Worlds League (Post-Jihad) Field Manual: 3085, pp. 233-234
Affiliation: Lyran Commonwealth (Post-Jihad) Field Manual: 3085, pp. 234-235
Affiliation: The Inner Sphere Clans (Post-Jihad) Field Manual: 3085, p. 235
Affiliation: Ghost Bear Dominion (Post-Jihad) Field Manual: 3085, pp. 235-236
Affiliation: Raven Alliance (Post-Jihad) Field Manual: 3085, p. 236
Affiliation: Major Periphery (Post-Jihad) Field Manual: 3085, pp. 236-237
Affiliation: Minor Periphery (Post-Jihad) Field Manual: 3085, p. 237
Affiliation: Independents (Post-Jihad) Field Manual: 3085, p. 237
Affiliation: Terran (Post-Jihad) Field Manual: 3085, pp. 237-238
Affiliation: ComStar (Post-Jihad) Field Manual: 3085, p. 238
Affiliation: Republic of the Sphere First Generation (Post-Jihad) Field Manual: 3085, p. 238
Stage 0: Clan Sub-caste: TankWarrior Era Report: 3145, p. 189
Affiliation: Republic of the Sphere (Dark Age) Era Report: 3145, pp. 183-184
Affiliation: Capellan Confederation (Dark Age) Era Report: 3145, pp. 184-185
Affiliation: Draconis Combine (Dark Age) Era Report: 3145, p. 185
Affiliation: Federated Suns (Dark Age) Era Report: 3145, pp. 185-186
Affiliation: Free Worlds League (Dark Age) Era Report: 3145, pp. 186-187
Affiliation: Former Free Worlds League (Dark Age) Era Report: 3145, p. 187
Affiliation: Lyran Commonwealth (Dark Age) Era Report: 3145, pp. 187-188
Affiliation: Inner Sphere Clans (Dark Age) Era Report: 3145, pp. 188-189
Affiliation: Rasalhague Dominion (Dark Age) Era Report: 3145, p. 189
Affiliation: Raven Alliance (Dark Age) Era Report: 3145, pp. 189-190
Affiliation: Major Periphery (Dark Age) Era Report: 3145, pp. 190-191
Affiliation: Minor Periphery (Dark Age) Era Report: 3145, pp. 191-192
Affiliation: ComStar (Dark Age) Era Report: 3145, pp. 192-193
Stage 1: Born Mercenary Brat (Dark Age) Era Report: 3145, p. 192
Stage 2: Adolescent Warfare (Dark Age) Era Report: 3145, p. 193
Stage 2: Mercenary Brat (Dark Age) Era Report: 3145, p. 193
Stage 3: Family-Trained Warriors (Dark Age) Era Report: 3145, p. 193
Stage 4: Cloister Training (Dark Age) Era Report: 3145, p. 193
Stage 4: Goliath Scorpion Seeker (Dark Age) Era Report: 3145, p. 193
Stage 4: ComStar/Word of Blake Service (Dark Age) Era Report: 3145, p. 193
Stage 4: Tour of Duty (Dark Age) Era Report: 3145, p. 193