What gives it the designation "Stealth" on the ship page?

This is an error on the webstore due to a mix up on the internal design page and it should say Light Fighter and has been corrected. However the Stealth part is still valid, in reference to the class of components with which the Arrow can be fitted. Utilizing stealth components could allow the Arrow to be used as a patrol craft without being seen, or in an ambush to surprise one's enemies.