An end user agreement is, in simple terms, a contract. Federal law says nothing in particular about them, cntract law is a well codified and understood area of civil law.
Common law.
A codified law.
Federal law, and codified by all states, declare that this is the legal age for aclochol consumption.
law of nations
There is no such codified law that I am aware of.
A government is not codified and cannot be codified. What can be codified is the law. There was not anyone who unified the Roman Empire because the Roman empire was never divided. Maybe you have in mind Justinian I who commissioned the Corpus Juris Civils (Body of Civil Law) also known as the Justinian Code. This work codified Roman civil law.
It is a change in a codified law.
Statutes are laws, and laws are stautes. The words are synonymous.
Tribonian
No. It is based primarily on common law. It is developed by Judge made Law (also klnown as common law) over centuries. However, over time, many aspects have been codified within the statutes of each state and federal jurisdiction.
No. Vandalsim is an offense that is codified in the statutes of the indiviual states. There is no federal law addressing this issue. They are trying to reduce it but they get bored at the weekend like everyone else.