Video Captioning Style Guide

General

Captions should include:

• All words spoken by characters (including stuttering etc).
• Words spoken by a narrator.
• The words to any song.
• Identification for off screen speakers.
• Descriptions of sound events that impact on the story or meaning.

Captions should not include:

• Every word or sound effect where the pace of a video sometimes makes it impractical.
• Information that is already displayed on screen, e.g. text in a Powerpoint slide.

Font

• Characters should use a white san serif font, such as Arial or Helvetica.

Background

• Captions should have a black background box.

Sentence Style

• Each sentence should use a mix of uppercase and lowercase letters.
• Punctuation should follow normal style and conventions.
• Punctuation should convey, as much as possible, the way speech is delivered.
• Use ellipses when there is a significant pause within a caption (e.g. It's so...majestic).
• In order to maintain reading rate, non-essential information can be removed.
• Spell out numbers from one to ten, but use numerals for all numbers over ten.

Spacing

• Each line should be no more than 37 characters in length.
• Each caption should run over no more than two lines.
• Line and caption breaks should reflect the natural flow of the sentence and its punctuation.

Timing

• Captions should coincide with the relevant soundtrack, to preserve the relation between sound and visuals.
• The reading speed should not exceed 180 words per minute (3 words per second).
• The pace of a video sometimes makes it impractical to include every word or sound effect in caption form.
• No sentence should remain on screen for less than 2 seconds.

Sound and Speaker Identification

• Any noise or music that enhances the visuals, contributes to characterisation or adds atmosphere should be captioned.
• Sound effects should be shown in square brackets, e.g. [dog barking]
• The speakers name should be identified in round brackets, e.g. (John)
• Speakers names and sound effects should be shown on a line of their own,e.g.
  (Bill)
  I don't think your solution
  would work in this case.

Further Information

This style guide is based on information contained in the following documents:

• 'Captioning Key', U.S. National Association of the Deaf
• 'Transcription Guidelines for Captioning', CaptionSync
• Captioning Quality Code of Practice, Deafness Forum of Australia
• Designing accessible Student Support materials and instructional media