The badge, which displays sperm cells swimming in waves, can be won by correctly answering 10 out of 13 questions about sex.

"You need a license to drive a car and you should have a sex certificate that shows you don't take health risks. This is done seriously and with humor and the goal of course is to get more people using condoms," said RFSU manager Tone-Berit Lintho.

The summer is also high season for sex and sexually transmitted diseases and the RFSU specializes in attention-getting campaigns to promote safe sex.

A recent survey of this year's 'russ' - the reveling high school graduates who go wild for three weeks of debauchery before final exams - revealed the teenagers have a lot to learn.

* While 75 percent of Norwegian youngsters are positive towards condom use, only 1 in 5 actually used them when last having sex.

* Fully 90 percent of Norwegian boys believe 'no' means 'maybe'.

* Three out of four youths put the condom on incorrectly and many bite open the package, creating the danger of condom puncture.

Contraction of venereal diseases and HIV reached a new high last year, and an average of 45 Norwegians a day contracted chlamydia.