Writing Style Guide

The most important points of the style guide include:

• Avoid passive voice.
  • Active voice writing is stronger and direct. Active voice simplifies doc translations.
• Use sentence-case headings.
  • Sentence case creates more casual and approachable writing.
• Wrap lines at 80 characters.
  • Line wrapping improves review feedback.
• Use present tense and avoid "will."
  • Docs cover actions happening now and the results in real time.
• Spell out numbers less than 10, except for percentages, time and versions.
  • Numbers in sentences are more difficult to read.
• Capitalize "Crossplane" and "Kubernetes."
  • Crossplane and Kubernetes are proper nouns. Don't use k8s.
• Spell out the first use of an acronym unless it's common to new Crossplane users. When in doubt, spell it out first.
  • Avoid assuming the reader already knows the background.
• Don't use cliches.
  • Cliches make writing sound unprofessional and aren't internationally inclusive.
• Use contractions for phrases like "do not," "cannot," "is not" and related terms.
  • It's easy to miss "not" in "do not." It's hard to misunderstand "don't."
• Don't use Latin terms (i.e., e.g., etc.).
  • These terms are more difficult for non-Latin language speakers to understand.
• Avoid gerund headings (-ing words).
  • Gerunds make headings less direct.
• Try and limit sentences to 25 words or fewer.
  • Longer sentences are more difficult to read. Shorter sentences are better for search engine optimization.
• Be descriptive in link text. Don't use "click here" or "read more".
  • Describe link text improves accessibility for screen readers.
• Order brand names alphabetically. For example, AWS, Azure, GCP.
  • Ordered names removes the appearance of preference.
• Don't use "easy," "simple," or "obvious".
  • It's condescending to the reader.
• No Oxford commas.
  • A subjective style choice. No commas before "and" or "or."
• U.S. English spelling and grammar.

Crossplane relies on Vale to enforce the complete style guide.

Read more about [using Vale with the Crossplane documentation]({{<ref "Vale" >}}).

Italics

Use italics to introduce or draw attention term.

Use italics on the same term sparingly.

Inline code styles

Use inline code styles, single ticks (`) for files directories or paths.

Use the {{</* hover */>}} shortcode to relate command explanations to larger examples.

Placeholders

Use angle brackets (< >) for placeholders. Use a short, descriptive name inside the brackets. Use underscores between words to simplify selections.

For example, to creating AWS credentials prompts for the key and secret key.

[default]
aws_access_key_id = <aws_access_key>
aws_secret_access_key = <aws_secret_key>

Styling Kubernetes objects

Kinds

Kinds should be upper camel case. Capitalize each word, without separators.

For example the {{<hover label="kind" line="4" >}}kind: MyComputeResource{{< /hover >}} capitalizes "My," "Compute" and "Resource" with no spaces or dashes.

spec:
  group: test.example.org
  names:
    kind: MyComputeResource

Names

Object names should use snake case. All words are lowercase with dashes (-) between them.

For example the {{<hover label="kind" line="4" >}}name: my-resource{{< /hover >}} uses all lowercase. A dash separates "my" and "resource."

apiVersion: test.example.org/v1alpha1
kind: MyComputeResource
metadata:
  name: my-resource

Inline

Kubernetes objects mentioned inline don't require styling unless drawing special attention.