COLUMBIA - The South Carolina Ethics Commission is cautioning candidates in next month's primary runoff not to accept donations that put them over the per-cycle state limit.

The commission released an advisory opinion Monday about a quirk in state law regarding when a donation can be applied to a primary runoff.

Runoffs are held two weeks after the primary. But when it comes to donations, the runoff cycle doesn't start until a week after the primary. Donors who already gave the maximum $3,500 toward a primary can't contribute again until eight days later.

The commission says it won't punish former candidates, noting they received bad advice.

Candidates in 2010 who had excessive contributions because of that quirk include Gov. Nikki Haley and her Democratic challenger, Vincent Sheheen, and Attorney General Alan Wilson.