▁A RO S ▁operating ▁systems ▁include ▁a ▁be ep ▁command . ▁A ▁be ep ▁command ▁is ▁also ▁part ▁of ▁ASCII ' s ▁MS X - D OS 2 ▁Tools ▁for ▁MS X - D OS ▁version ▁ 2 . ▁ ▁Use ▁in ▁transport ▁Be eps ▁are ▁also ▁used ▁as ▁a ▁warning ▁when ▁a ▁tr uck , ▁l orry ▁or ▁bus ▁is ▁revers ing . ▁It ▁can ▁also ▁be ▁used ▁to ▁define ▁the ▁sound ▁produced ▁by ▁a ▁car ▁horn . ▁Col lo qu ial ly , ▁be ep ▁is ▁also ▁used ▁to ▁refer ▁to ▁the ▁action ▁of ▁hon king ▁the ▁car ▁horn ▁at ▁someone , ▁( e . g ., ▁" Why ▁did ▁that ▁gu y ▁be ep ▁at ▁me ?" ), ▁and ▁is ▁more ▁likely ▁to ▁be ▁used ▁with ▁vehicles ▁with ▁higher - p itch ed ▁horn s . ▁" H onk " ▁is ▁used ▁if ▁the ▁sound ▁is ▁lower ▁pitch ed ▁( e . g . ▁Volks wagen ▁Be et les ▁be ep , ▁but ▁Old sm ob iles ▁hon k ▁. ▁On ▁trains , ▁be eps ▁may ▁be ▁used ▁for ▁communic ations ▁between ▁members ▁of ▁staff . ▁ ▁Use ▁in ▁tele communic ation ▁A ▁be ep ▁is ▁also ▁considered ▁a ▁col lo qu ial ism ▁to ▁describe ▁a ▁second ▁tele phone ▁call ▁coming ▁in ▁on ▁the ▁same ▁phone ▁line ▁as ▁someone ▁is ▁currently ▁speaking , ▁either ▁on ▁a ▁land line ▁or ▁mobile ▁phone . ▁The ▁call ▁waiting ▁feature ▁often ▁outputs ▁an ▁aud ible ▁" be ep " ▁noise ▁to ▁indicate ▁that