- object
: BLGlobalField
- octopole
: BLCMDmultipole
- offset
: BLGroup
, BLGroupElement::Child
, BLGroup::Child
- omega
: BLCMDpillbox
- oneNTuple
: BLCMDtrace
- openAperture
: BLCMDgenericbend
, BLCMDgenericquad
, BLCMDmultipole
- ors
: BLCMDpolycone
- outerRadius
: BLCMDabsorber
, BLCMDsphere
, BLCMDtubs
, BLCMDpillbox
, BLCMDtorus
, BLCoil
, BLCMDpolycone
- outline
: BLCMDmovie
- overallLength
: BLCMDpillbox
g4beamline