Degree of nobility

For nobles, the order of distinguishment goes duke, marquis, count, viscount, baron, baronet.

Mores
Generally nobles could not oppose to higher level nobles.

During gala parties, it's usual that the guests dance, but only in degree order. The higher degree nobles dance first, followed by the lower degree ones.

It's also usual nobles get marriage with another nobles, but it's possible nobles get marriage with commoners.