out-side forward inside back bracket

inside forward inside back counters

inside forward inside back rockers

out-side forward inside back three

inside back edge in eight form

inside back loop

inside forward double three

inside forward edge in eight form

inside forward outside back three

left inside forward

right inside forward

back-forward reflection

feed-forward back-propagation network

forward forward deposit

forward-back-scattering type laser current meter

inside to inside

forward-backward counter (=forward-reverse counter)

angles back to back

Back filling at abutment back of Bridge or culvert