It is used principally for recreation by the local population.

It is used principally as a means of prison discipline.

This system is unofficial and principally used by Western players.

It is typically used principally to provide services to passengers.

It was principally used for flash photography in the early 20th century, but had other uses as well.

The remains of the buildings were used principally for various agricultural purposes.

It has six tracks and is used principally for passenger trains.

The area, being on alluvium, was principally used for market gardens.

It is used principally in the production of milk.

A few western charts show full l- and r- series, used principally for loan words.