Professionalism and Ethics
Business writing should be consistently written in a professional tone suitable to the the targeted audience.
Here are some links that can be helpful:
Writing in a gender-neutral way Links to an external site.
The Dos and Taboos of body language around the world Links to an external site.
** Extra reading** -- Dos and Taboos -- Humor Around the World Links to an external site.
Projecting Professionalism when you communicate Links to an external site.