... Circles are chemically normal stars, squares are Boo stars, the diamond is the possible Bp star V380 Ori A. Open symbols are stars with confirmed magnetic field detections. ... The photospheres of about 10-20% of main sequence A- and B-type stars exhibit a wide range of chemical peculiarities, often associated with the presence of a magnetic field. ... The incidence of Boo chemical peculiarities we find in Herbig stars is much higher than what is seen on the main sequence. ...