Microsoft Word's red and green squiggles suggesting spelling and grammar corrections don't look great on a resume. Even if you click "ignore" to get rid of those lines, they'll still show up when others open the doc. Prevent this from happening with Word's document protection.
Sample resume snippet from About Job Search.
Reddit user Kevspace2 offers this tip for making your resume look more professional. When you make a document read-only, it preserves the formatting and gets rid of all the squiggly lines. That includes Word's mistaken advice to correct your name, company names and fragments in your resume.
Of course, if your potential employer allows PDF resumes, you should send a PDF version instead, but this tip is helpful for those employers who demand a Word doc. Go to Tools > Protect Document > Read Only for a squiggly-free resume.