Follow the standard capitalization rules for American English. Additionally:

  • Follow the official capitalization for the names of brands, companies, software, products, services, and terms defined by companies and open source communities.

    • For example, if you're using Kubernetes-related terms, then follow the capitalization shown in the Kubernetes Concepts documentation.

      Recommended in a Kubernetes context: A Job creates one or more Pods.

      Recommended: The Cloud Scheduler job publishes a message to a Cloud Pub/Sub topic at one-minute intervals.

    • If an official name begins with a lowercase letter, then put it in lowercase even at the start of a sentence. But it's better to revise the sentence to avoid putting a lowercase word at the start, if possible.
  • Don't use all-uppercase, except in the following contexts: in official names, in abbreviations that are always written in all-caps, or when referring to code that uses all-caps.
  • Don't use camel case, except in official names or when referring to code that uses camel case.

Capitalization in titles and headings

In document titles and headings, use sentence case. That is, capitalize only the first word.


  • For proper nouns, trademarks, keywords, and other terms that are always capitalized a certain way, use the standard capitalization for the term, regardless of where it appears in the title or heading.
  • If you use a colon in a heading, treat what follows the colon as a separate heading, with an initial capital letter of its own.
  • When you refer to the title of a third-party work such as a book or a movie, use the same capitalization used in the work. (In most cases, that means title capitalization.)

Even though you're using sentence case, don't put a period at the end of a heading.

Capitalization and colons

Use a lowercase letter to begin the first word of the text immediately following a colon, unless the text is one of the following:

  • A proper noun (Open source software: Istio).
  • A heading. See also Capitalization in titles and headings.
  • A quotation (Arthurian wit: "Bring me yon sworde").
  • Text that follows a label such as Caution or Note.

Capitalization and figures

Use sentence case for captions. Use sentence case for labels, callouts, and other text in images and diagrams.

Capitalization in glossaries and indexes

Use lowercase for glossary and index terms unless the term is a proper noun or has another reason to require capitalization.

Use sentence case for glossary definitions.

Capitalization and hyphenated words

When a hyphenated word is the first word in a sentence or in a heading, capitalize only the first element in the word, unless a subsequent element is a proper noun or proper adjective.

Capitalization in lists

Use sentence case for items in all types of lists. For more information, see Capitalization and end punctuation on the Lists page.

Capitalization for tables in text

Use sentence case for all the elements in a table: contents, headings, labels, and captions.