Knight Code of The Rainbow Millennium

During the Silver Millennium, Knights--also known as "kamen" or "male senshi"--were the oft-maligned male carries of Sailor Crystals. Their power was intrinsically lesser than their female counterparts, partly due to their inability to utilize their elemental powers as effectively and partly due to a set of restrictions imposed on them since time immemorial...

A Knight will protect all those whom possess Sailor Crystals within the Solar System.

A Knight is not supposed to favor one Sailor Senshi or Knight over another. It is feared that a Knight may choose to sacrifice one Senshi's life in order to preserve the life of another more beloved soldier.

A Knight may not use the name of his star in his alias.

Showing the title of one's star indicates that the Knight has more pride and devotion to his own moon or planet than the moon or planet of another Senshi. The title is also masked so that the Knight will not be associated with the positive or negative reputation of his star. (Or vice versa.)

A Knight must keep his sailor crystal within his body or in the care of his parents except in extreme circumstances.

Displaying and using a crystal is another form of association with a star, similar to showing it's title. Knights are also traditionally not trusted with large amounts of power. This is because most Moons and Planets during the Rainbow Millennium considered men less emotionally stable than women, and therefore were unwilling to make them responsible for something as incredibly powerful as a crystal.