Here are a few specific items I can remember off the top of my head. I will add more in the comments as I find them

• Fusion reactor has few details
• Golden Module is missing
• Many reactor components have few details
• Details on the concept of re-enriching the various rods is missing entirely as far as I can tell

Edited by Speiger:

• Removed Elytra Modul since it is not part of ic2c

@Maoman1 thanks for the report.
Could you please specify for the Fusion Reactor "What is missing?"
I don't want a novel or the exact wiki entry but a rough shape of "What is missing according to you?"

@Maoman1 I updated these entries based on how much information you have given me.
Since that was very little there was only very little that was changed.
To be fair you won't be able to answer but if you ask "FIX IT" without context (like this one mostly was) you will get not much.