Carbon Design System — Writing Style

Capitalization

Sentence case everywhere

Use sentence-case capitalization for all UI text elements — predominantly lowercase. Capitalize only the first word and proper nouns.

Examples: form labels as "First name" and "Email address."

Carbon's rationale: "Sentence-style capitalization makes it easy for readers to distinguish between common nouns and proper nouns, and is generally considered the quickest form to read."

Do not capitalize:

Names of UI features or components unless they are sold separately or trademarked
Words to convey "specialness" or importance — this is subjective and creates inconsistencies
Anything not in the approved capital-use list

Do capitalize:

"Carbon" and "Carbon Design System"
IBM and all company/organization names
Official, trademarked products and services
Initialisms (IBM, BBC, HTML) and acronyms (NASA, GIF)
People's names, country/place names
UI labels when referenced in body copy (match the label's capitalization)
First word of a sentence or phrase

Title case: never for UI

Title case (first letter of most words capitalized) is not used for UI copy. Carbon gives two reasons:

It requires complex grammatical judgment calls about which words to capitalize
It slows reading because readers cannot distinguish proper nouns from common nouns

All caps: never

All-caps is slower to read because individual letter shapes are less distinguishable. It also makes proper noun distinction harder.

Simple writing

Use the simplest term appropriate for the audience: "large" not "voluminous," "small" not "diminutive"
Keep sentences as short and simple as possible
Omit wordy or redundant phrases
Respect the user's time: trim to as few words as possible, but don't be terse
Avoid "please" and "thank you" in UI — these terms are culturally inconsistent and can feel inappropriate
Create a product-specific terminology list: preferred terms and terms not to use

Present tense

Use simple present tense. Avoid verb tenses with "have," "has," "had," "been," "should," "would," and "will" unless necessary.

Conversational style

Frame content as a conversation between the product and the user. The conversational level depends on where the user is in their journey.

Contractions: Use when they fit context and improve flow. "Don't" not "do not."

Sentence openers: Beginning with "and," "but," or "so" is acceptable when it allows shorter, more scannable sentences. Don't overuse.

Exclamation marks: Use only for positive messages. Never for negative messages or errors. Maximum one per context (per window or per page). Example of correct use: "Your IBM Cloud account is ready!" Example of incorrect use: "You have reached your usage limit!!"

Terms of politeness ("please," "thank you"): Use only when the user is being genuinely inconvenienced. Do not use superfluously.

Correct use	Incorrect use
"Indexing might take a few minutes. Please wait."	"Please create a subscription account to get full access."

Can / may / might

Use "can" to express ability ("You can use the command line interface")
Use "may" to express permission or uncertainty — avoid when "can" is meant
When "may" and "might" both work, use "might" to avoid confusion with "may" (permission)

Inclusive language

IBM is committed to eliminating language that supports racial, cultural, or gender bias. All words in product offerings must be inclusive.

Carbon refers writers to the IBM Terminology database for guidance on specific terms and the IBM Inclusive IT Terminology resource for broader context.

Pronouns

Use second person ("you," "your") as often as possible — it is friendlier and more engaging.

Use first person ("my," "my account") only for headings or labels that are specific to the user's personal data. In explanatory text for those labels, switch to second person.

Use first person plural ("we," "our") when referring to IBM, particularly in requests for user data — e.g., "Why do we need your email address?"

Avoid gender-specific third-person pronouns; use "they/them/their" for unknown or irrelevant gender.

Active and passive voice

Default to active voice. The subject clearly acts on the verb.

Active	Passive
"Next, the admin configures access privileges."	"Next, access privileges are configured by the admin."

Passive voice is acceptable when the true subject is a system and the human is secondary, or when the passive is genuinely more natural.

Acceptable passive	Why
"The database needs to be rebooted."	The actor (the system) is the natural subject, not a person