TL; DR: Many T2 blueprints disagree with Advanced Construction Skillbooks.
So been spending time getting into T2 industry, and something I have seen for all T2 craft is a fight between Skillbooks and the T2 BPC’s.
For instance, A Eos (Command Battlecruiser) BPC claims L1 Of Advanced Medium Ship Construction is all that is needed, meanwhile the skill Advanced Medium Ship Construction claims L5 is required, and L4 for most all other T2 cruisers.
I suspect the BPC is correct, but it is still a little confusing over all. T2 small ships has the same problem. Advanced Large Ship Construction is different, the skill doesn’t list any ships at any levels!
I know its likely just a data entry problem, but it is confusing when trying to pick which skill to train, and (hopefully) should be a quick thing to fix.