Ten thousand people have signed up to volunteer at the Republican National Convention (search), but city officials are bracing for the possibility that some won't show up as a form of protest.

Groups planning protests during the Aug. 30-Sept. 2 convention at Madison Square Garden have been encouraging activists to sign up to volunteer and then either not report for duty or show up and cause trouble.

"Fill out the volunteer forms. Be polite, dress appropriately, and smile a lot" during the application process, says a Web site dedicated to the sign-up-and-abandon strategy, run by Philadelphia resident David Lynn.

The site then says: "Don't show up for your volunteer assignment. Don't call in sick, don't give any warning — just don't show up." Activist-volunteers are also being sought for the Democratic convention, July 26-29 in Boston.

New York's convention volunteer operation assumes that some of those who've registered online since the start of a recruitment effort in April will not show for various reasons, said Paul Elliott, a spokesman for the host committee.

"It's not a concern," he said. "On the opening day of the convention, we will be completely prepared in terms of staffing and deployment of resources." Volunteers are needed to welcome delegates, journalists and others; help with transportation and work in the media center.

Lynn said Thursday he doesn't know how many people are heeding his call, but that the volume of hits to his Web site and the e-mails he has received indicate the movement is popular.

"We're never going to be able to count, but I think they're in trouble," he said.

The host committee, which plans to enlist 16,000 volunteers, acknowledges it is possible for a determined protester to make it through all steps in the screening process, which includes asking for Social Security and driver's license numbers.

But Elliott said protesters who plan actions to disrupt convention events are misguided because the result would be a protest against the Big Apple, as well.

"A good convention means success for New York," he said.