When President-elect Barack Obama mentioned in his acceptance speech that his campaign began "on the front porches of Charleston," among other places, some local purists may have winced.

After all, the keepers of this city's architectural flame don't call them "porches" but "piazzas." And they're most often located on the side, not the front, of the house.

The term "piazza" first appears here around 1730, probably brought here by visitors or settlers from the Caribbean, says Carl Loundsbury, an architectural historian with Colonial Williamsburg and author of "An Illustrated Glossary of Early Southern Architecture and Landscape.

"It seemed to have worked its way up the coast as a synonym for open porch," he says. "There's another meaning of that term, which is a corruption of the Latin and Italian piazza, meaning open square."

This corruption came in London, fortunately, not the United States. When master architect Inigo Jones designed St. Paul's Church at Convent Garden, people began using the term for the open space but applying it solely to the sheltered area.

Loundsbury says the term "piazza" also reached into Virginia and even New England during the 18th century but gradually died off there as people began using "porch" instead.

No one is sure why the term piazza survives here while vanishing most everywhere else, but "The Buildings of Charleston" author Jonathan Poston has a guess.

"The real architectural usage of it has become pretty uniquely Charleston, and it's part of the fact that Charleston's traditions do hold onto things like that," he says. "That is a tradition."

Poston is inclined to give the president-elect a break on the usage, especially because he was talking to the nation as a whole and not simply to Charlestonians and its educated visitors.

Charleston Preservation Officer Eddie Bello says he thought Obama's reference was great, adding "it makes me proud that my job is to help preserve those porches. I already had goose bumps while listening to the speech, but to have Charleston mentioned during such an inspirational and historic moment for our country was just remarkable."

In fact, it's mostly the old porches —those built on the city's thousands of single houses from the 18th and 19th centuries — that are called piazzas.

The fancy term probably rarely has, if ever, been used by the builders or owners of the many, many more 20th century homes built in the area.

Still, it was one of the city's older homes that apparently inspired the remark. Obama held an April 2007 fundraiser at 21 King St., a grand Italianate sidehall house built between 1852 and 1870.

Bello says had he attended that $1,000-per-plate fundraiser —"I'm sure my invitation must have simply been misplaced" —he would have explained to Obama that they are actually side piazzas.

"I would have even helped him with the proper pronunciation (pee-AZ-ah)," Bello said. "He'll have to come back soon so we can sit down and discuss."

Regardless of whether Obama does that, the slip alone likely won't cost him any votes here should he seek re-election (and shouldn't that campaign be starting soon?)

After all, it's not like he said his campaign began "on the front verandas of Charleston."