Here's are a couple articles about China's special visa practices for people from the Jammu and Kashmir region of India in 2009. [1] [2] I wasn't aware of this contemporaneously, so I don't know quite what it was about, but it sounds like if you were from Jammu and Kashmir, your visa would be issued as a paper visa, and if you were from the rest of India, it would be issued as a stamp. A quick look at sample US passports indicates place of birth including state, so it would be feasible to implement.

My dictionary [3] has many definitions for citizen, none of which are very specific about being ascribed to a country, although the example does use a country:

> 1 : an inhabitant of a city or town especially : one entitled to the rights and privileges of a freeman

> 2a : a member of a state

> b : a native or naturalized person who owes allegiance to a government and is entitled to protection from it

> // She was an American citizen but lived most of her life abroad.

> 3 : a civilian as distinguished from a specialized servant of the state

> // Soldiers were sent to protect the citizens.

[1] https://economictimes.indiatimes.com/nri/visa-and-immigratio...

[2] http://blogs.reuters.com/india/2009/10/02/why-is-china-issui...

[3] https://www.merriam-webster.com/dictionary/citizen