What does it mean when it says "Second Majors are NOT Considered"?

Ill provide an example as it will be easier, but lets say I wanted to major in Petroleum engineering. That major says that “Second Majors are NOT Considered”. Does that mean that if Petroleum engineering is put as a 2nd major, then it will essentially be ignored? Or does it mean that if you put you put petroleum as your first choice, then whatever your 2nd choice major may be, that will be ignored. Does anyone know? I would be so grateful if anyone could reply!

It means that they only consider those applicants who put petroleum engineering as first choice. Yes, those who put petroleum engineering as 2nd choice will be denied by Petroleum engineering department automatically.

Thank you so much for replying! I was so unsure and I couldnt find any sources on it.