General Rule:
* "Arab" should be capitalized when referring to the people or culture of the Arab world.
* "nomadic" is an adjective and should not be capitalized unless it's the first word of a sentence.
Examples:
* Correct: The Arab culture has a rich history of nomadic traditions.
* Correct: Nomadic Arabs have played a vital role in the development of the region.
* Incorrect: The Nomadic Arabs have a rich history.
Specific Cases:
* If "nomadic Arab" is used as a proper noun (a specific group with a recognized name), it would be capitalized. For example: "The Nomadic Arab tribe of the Bedouin are known for their hospitality."
In summary:
* Capitalize "Arab" when referring to the people or culture.
* Don't capitalize "nomadic" unless it's the first word of a sentence.
* Capitalize "Nomadic Arab" if it's a specific, recognized group name.