A good one is Becca.
Many just use Becky.
If she's from America's South, it would probably be Reb.
I have a friend named Rebecca. She goes by Becky.
Pocahontas's nickname is Rebecca.
Danielle because I can't stand the nickname Becca. But just Rebecca alone is nice.
It is a diminutive of, or nickname for the name "Rebecca" or "Rebekah".
His real name is Niklaus. 'Nick' is just a modern nickname for him.
A good nickname for the name London could be Loni or Lundy.
A good nickname for the name Laura could be Lulu or Rory.
"Hub" could be a good nickname for the name Hubbard.
"Jules" could be a good nickname for the name Juliana.
Des or Dez could be good nickname options for the name Desmond.
A black person can have the same nickname as anyone else. It might be based on their name such as Becky for Rebecca, or Bill for William. Or it might be a nickname someone has given them or that they have chosen for themself.
The English name for Pocahontas was Rebecca Rolfe. She is known for her role in the settlement of Jamestown, Virginia.