I'm not sure what you mean by a utility plug-in. As far as 'Require' and 'Contribute' bits, they're rather simple once you understand them. What you see may be different from what I explain as I'm going by how Mission Computer works, not EVNEW.
When you access something where you can edit Require and Contribute bits, you'll see a grid of check boxes. each box corresponds to one bit, which is either Require or Contribute depending on which type you're editing. They can be set in shΓ―p and oΓΌtf resource types. A bit is set when it is checked.
If you set a Require bit in a certain outfit or ship, then the player needs the same Contribute bit to be set before they can buy that ship or outfit. If a ship or outfit has several Require bits set in it, the player needs all of the same Contribute bits to be set.
This way, you can make a ship that requires the player buy a particular outfit before they can buy the ship. This is how the licenses in EVN work. Each license sets one Contribute bit for its type, and each ship has corresponding Require bits set for each type of license it requires the player to buy.