Captioning Guide

captioning icons

Captions are the text version of a video’s audio content with additional timing information which allows them to appear on screen in time with the video. SRT files are the most common caption file used by online video players such as YouTube and Vimeo. They are considered the most basic of all caption file formats. They are essentially a text file with very specific formatting, allowing them to be opened and edited by most programs. Because of their basic structure, SRT files do not support any coloring or positioning – meaning captions appear as all white text at the bottom of the screen.  Remember captions may be used by any one viewing your video.

What are Good Captions?

Good captions are easy to read, accurate and easy to understand. A good grasp of English grammar and punctuation rules are essential to making good captions. Here are some quick tips: Captions should accurately reflect the audio.

  • The timing of captions should coincide with the audio.
  • Captions should break at natural linguistic breaks.
  • It should be clear from the captions exactly who is talking.
  • Sound effects should be adequately described.

How to Format Captions?

Captioning has a few rules that make them work best for all.  Principally you want them to be soft enough to not be hard to read, and no longer than two lines, but never break the meaning of structure English – such as in the middle of a verb or noun clause.


The readability of captions is improved when the caption lines end at natural linguistic breaks and reflect the natural flow and punctuation of a sentence. As a general rule, keeping chunks of meaning together improves readability. Each caption should form an understandable segment.

  • Keep subjects and phrases together within the same caption.
  • Split ‘around’ verbs – verbs are often the best place to start or end a caption or line break.
  • If words in a caption can fit on one line, they should.
  • Never break a verb before its negative: “they should (then break before ‘not’’.”

Labelling the Speakers

When more than one person is talking, then use the convention of a dash before the speaker, and another before the next speak.  This will help the person watching the captions to know that the speaker has changed.  Deaf and Hard of Hearing folks may not know there has been a change without that – showing them a change has occurred – even if they can see the person’s mouth moving.

If the person speaking is not on screen, identify the speaker with a dash and [Voiceover].

I.e. – [Voiceover]. If you’ve seen the person on screen previously and they are speaking without their face being visible, you should identify them by their name. E.g. – [Henri]


Captions should not be more that 7 seconds long

Recommended caption length is 1 second

Captions should start and end during the same time the audio is heard, and not start before or end afterwards.

Sound Effects

Audible content that is not speech can be marked and presented in the captioning – usually this is done in parentheses.

(Sound of train whistle)– when a train is coming into the station; (Knock at door) when the video shows a door with the person knocking on the other side unseen.


Unidentified sound track can be labelled like (music plays)

Track that is a song people will be familiar with (‘SURFING WITH THE ALIEN’ BY JOE SATRIANI PLAYS)  — you use title and artist)

When lyrics are involved that people can hear clearly, then type each captioned caption proceeded and ending with the # sign.

 Other Sound Devices

When people alter their voice, have accents or use alternative stress to be funny, sad, sarcastic, mean spirited. You can also place into the caption in parentheses an adjective that will help those who can’t hear this change.

You look wonderful (sarcastically)

I vant to suck your blood (Dracula-like)

Another issue would be when some whispers or mouths words. (Mouths) I love you!


Captions should reflect what someone has said even if their grammar is wrong or they repeat words or phrases.

You can correct ums, hums, and other non-word elements, deleting them from the record.  You can spell out the words even if they are mispronounced.  Such as “Warshington” for “Washington.”


Correct Incorrect
Current ministers (Vice president, Secretary of State) General political terms (“the minister said,”
Political parties (Republican Party, the Republican Party, the Democratic Party, Independent, etc.)


Terms like ‘commission’ and ‘inquiry’, unless as part of an official title (“a state commission into

abuse”, but “The Commission of Audit”)


Opposition Leader and the Opposition (for current title holders only) Police, unless using full official title (“the police arrived on scene”, “the matter was referred to New York Police Department”)


The Government, when talking about the currently sitting party of government
Federal, but usually only when paired with another capitalized word, or as part of a title (“the

Federal Government”, “a federal initiative”)


Business titles (“managing director Jacob Weisman”)


Mom and Dad, when used as titles (“I said to Mom”, but “I said to my mom”)


News reporters’ titles (“state political reporter Jerald Chia”, “US bureau chief Alfread Herald”)


Military titles, only when used as a personal title (“Major Sara Brighton”, but “the major spoke”)


Rules for Punctuation

Use the ellipsis to indicate interrupts either when someone pauses in their speech or when the are interrupted by another.

  • A pause to think, e.g. He wasn’t angry…he was just tired.
  • An interruption by another speaker, e.g. – I was walking along the road and I… – No, way!


__’       THE APOSTROPHE Not for plurals. Use for possessive. E.g. Lou’s cat is cuddly. The cat rubbed on the stranger’s leg.

__,       THE COMMA BEFORE: ‘though’ and ‘however’. AFTER: ‘thanks’ ‘oh’ ‘well’ Thanks, Gerald. Oh, I was expecting that, however I am not interested.

–         THE DASH Use for an additional comment or sudden change of thought. E.g. I had a great day today – then I saw you! Or: How to use a dash – correctly!

“ ”       THE DOUBLE QUOTE She said, “Use double quotes when quoting prose, a poem or conversation.

‘ ’         THE SINGLE QUOTE The answer is ‘A’. …

Number Rules

Use 4:00 or 4pm and not 4 o’clock or 4 p.m.

Write out numbers 1- 10 like one through ten.  After that use digits until you get to huge numbers like 1 million.


Have someone proofread your captions.  Especially if you make typos frequently.  Proofreading is even more significant if a service automatically captioned your file, such as in YouTube.


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