Help! I need to name my niche?

[Piggiepants]

The lastest title used by corporate entities to describe their charitable works and contributions to the community is "corporate social responsibility." So how about "CSR writer"?

What I would recommend instead, however, if you are trying a change is to use a more generic, rather than specific, title. I.e., just use 'writer' or 'marketing/communications specialist.'' This would suggest that you can write in a variety of styles, and they'll know you have a nonprofit background from the rest of your resume.