Sometimes it is the choice 10-cent word or two, a spot-on sublime or consummate, that is the giveaway. Maybe it is a series of suspiciously skilled turns of phrase, syntax the envy of Strunk and White, or some pitch-perfect metaphors that raise the red flags.

As college admissions officers sift through thousands of application essays penned by eager-to-please high school seniors, they increasingly encounter writing that sparkles a bit too brightly or shows a poise and polish beyond the years of a typical teenager.

With the scramble to get into elite colleges at a fever pitch and with a rising number of educational consultants and college essay specialists ready to give students a competitive edge, admissions officers are keeping a sharp lookout for essays that might have had an undue adult influence. In some admissions offices, such submissions receive the dubious distinction DDI, short for "Daddy Did It."

Colleges are now cross-referencing student essays against the SAT writing sample, and, if doubts linger, will ask for a graded writing sample or raise their concern with the student's high school guidance counselor. Harvard even passes along suspiciously strong essays to professors for a scholarly opinion.

"There's an awful lot of talk in the admissions profession about this," said William R. Fitzsimmons, Harvard's dean of admissions and financial aid. "It's very difficult to know how much of it is the student's own work. It's just very hard to spot."

The concern over heavy-handed adult involvement is mounting as the admissions essay has become a pivotal part of the application, a key way for students to stand out from the throngs of applicants with top grades and SAT scores. In the past five years, the percentage of colleges attributing "considerable importance" to the college essay has risen from 19 to 28, behind grades, strength of classes, and standardized test scores, according to the National Association for College Admission Counseling.

Admissions officers say they would almost never deny admission solely over a suspicious essay, unless they could prove it was plagiarized. There are many talented writers, and it would be a shame to misjudge them, they say. But at competitive schools that reject the vast majority of students, a hint of doubt can tilt the balance.

"The essay has over time become more important to the admission decisions, and that's trickling down to students," said Melissa E. Clinedinst, assistant director of research for the National Association for College Admission Counseling.

College administrators say that intense pressure to gain acceptance to selective schools has compelled parents to turn to high-priced essay editors and coaches.

"The euphemism we use is polished," said Parke Muth, an admissions dean at the University of Virginia. "If you're paying someone that much money, there shouldn't be fingerprints. But some essays have that sheen, that lemony-fresh smell that makes you wonder."