See <<downspout>>

A record which precedes a group of detail records, giving information about the group not present in the detail records; for example, ``beginning of batch 17.''

The unrecorded length of magnetic tape that enables the operator to thread the tape through the drive and onto the take-up reel without losing data or recorded music, speech, or such.

The streamer which initiates the first phase of each stroke of a lightning discharge; it is a channel of very high ion density which propagates through the air by the continual establishment of an electron avalanche ahead of its tip. Also known as leader streamer.

1. A short piece of blank film at each end of a strip of photographic film or reel of motion picture film, used to thread the film through the mechanism of a camera or projector.

2. Lines or rows of dashes or dots used to guide the reader's eye across a printed page.

In a hot-air heating system, a duct that conducts heated air to an outlet.