Brother HL-4000CN Service Manual page 300

Represents a document or paper and its flow
direction.
Represents a thermal, optical, or pneumatic signal
and its flow direction.
Means that the information indicated by the arrow is
1
after 1V.
Means that the information indicated by the arrow is
1
before 1V.
Means that the information in the entire figure or
1
frame is after 1V.
Means that the information in the entire figure or
1
frame is before 1V.
VI-3