RALEIGH — North Carolina's state school board is setting ground rules for education entrepreneurs who want to offer online-only classes to public school students whose parents opt out of existing classrooms.

The State Board of Education on Thursday approved new standards for virtual charter schools. The N.C. General Assembly last year lifted a statewide limit on the number of charter schools, but didn't address online versions of charters, which are public schools given special permission to operate outside many normal rules.

Since then, a for-profit company tried to set up a virtual charter school in a deal with the Cabarrus County Board of Education.

The current online public school offers online classes to students trying to keep up with coursework, interested in subjects unavailable locally, prepping for tests or seeking career planning help.