LONDON (CP) - He towers over his father and is now a composed, blond teenager for whom the childhood nicknames Wills and Wombat seem entirely inappropriate.

In fact, as Prince William turns 16 tomorrow, Sweet William or William the Conqueror - of teen hearts, that is - would seem more apt.

The elder son of Prince Charles and Diana, Princess of Wales, hits that milestone having endured a year that saw his world turned on its ear with the death of his doting mother.

As William celebrates his birthday, however, he is likely wondering about the results of his GSCEs, the all-important national school tests that separate the university-bound 16-year-olds from the less scholastically inclined.

Though many in the world felt they knew Diana, and by extension her sons William and Harry, 13, not that much is really known about the two.

The royal establishment has enveloped the princes in a cocoon designed to provide them with as private a childhood as possible.

True, images immediately spring to mind. William grinning broadly on his first day at his current school, Eton. William and Harry, eyes glued to the ground, bravely escorting Diana's coffin to her funeral.

But images only tell part of the tale. And constructing a rounded portrait of the future king is a bit difficult, given that little verifiable information is available.

The guard eased up slightly for the celebration of William's 16th birthday, with the palace providing smidgens of information about the prince.

William plans to study geography, biology and history of art for his A-levels, two years of preparatory studies for university. There is no word yet which university he will attend.

He likes computer games, but doesn't have a computer of his own. He would like to go on an African safari, as his father and brother did last fall. He is a keen sportsman, preferring rugby, football, swimming, water polo and tennis.

He likes to read and watch action films, and has a black Labrador named Widgeon.

His written answers to a series of gentle questions put by Press Association, Britain's news agency, show he's already developing diplomatic skills. He said he likes music - especially techno music - but demurred when asked to name favourite bands or performers.

The royal determination to give the boys privacy in which to grow has, for the most part, been respected by Britain's otherwise intrusive newspapers.

In fact, up until yesterday, the industry watchdog had received no complaints about treatment of the boys.

But a supplement on William in last weekend's Sunday Mail that speculated about a screening process for potential girlfriends appeared to have crossed the line.

He filed a complaint with the Press Complaints Commission, which later announced the issue had been resolved amicably.

It was a sharp and timely reminder that under the industry's code of practice, William is still off limits. The voluntary code of practice stipulates that the lives of children can't be poked into while they are under 16 or still at school.

The commission expects the papers to continue to respect that fact.

``The British press has been very restrained,'' says spokesperson Tim Toulmin.

Toulmin thinks the public would not tolerate newspapers hounding Diana's sons in the way they hounded her. Even if they wanted to, they would run a real risk the government will scrap a voluntary code for a legislated one.

``Just because Prince William is suddenly 16 doesn't mean to say that they can suddenly start poking long lenses at him,'' Toulmin insists.

``If they indulge in the sort of voyeuristic spectacles which in the past dogged Princess Diana . . . Parliament's going to look at the whole matter.''