Titles

Hola primos,

In doing my research I sometimes see names with the title "Don" or "Doña". Most of the times it's just their names with no titles.
Is their a significance to using Don or Doña during this time period.
Here is an example:

https://www.familysearch.org/ark:/61903/3:1:9392-3XYS-5?i=612

Manjarrez, or Manjarrés, is the family name. There are plenty of both examples with the above link.

I have also seen a "N" used for last names for Indians...sometimes for black people. Any significance to using this as well?
Any thoughts will be helpful.

Thanks,
Andelmo