A national anthem is a patriotic song or musical composition that is either recognized officially by a nation’s government and constitution or is accepted as such by convention through popular use.
I believe the answer is: precedent
In social setting, we can see a precedent in court ruling.
When a supreme court ruled a controversial case, the other courts would most likely use the ruling as a precedent to settle similar cases that might appear in the future.
The Incas lived in the Andes, which lie along the Western coast of South America.
More specifically, they lived in North-Westen coast of South America.
