# Capitalization

Source: /ux/style-and-usage/capitalization.md

- Summary: Write every label in sentence case: the first word capitalised, the rest lower, except proper nouns and acronyms.
- Status: Adopted, since 2026-10-02
- Principles: Maximum intuition, One way
- Surfaces: Screen, Email, Form, Document

## When to use

Use it on every label a person reads: fields, pages, tabs, groups, buttons, select options, headings and email subjects.

## When not to use

Proper nouns and acronyms keep their capitals, as in `LinkedIn` or `Cal.com`. Existing names in the live bases keep Title Case until the rename pass described below.

## How it works

### Capitalise the first word and nothing else

Write the first word with a capital and the rest in lower case. A proper noun or an acronym keeps its own capitals wherever it sits.

Pass: in every label, every word after the first is lower case unless it is a proper noun or an acronym.

Filter labels on a CRM contacts list.

Do: folk labels its columns Job title and My last interaction.
Image: /ux/sources/folk-people-list.webp

Don't: Square's columns read Item Name, Duration and Price.
Image: /ux/sources/dont-square-title-case-columns.webp

Replace this: Due Date
With this: Due date
Replace this: Expected Close Date
With this: Expected close date

### Use the same case on buttons, tabs and options

Buttons, tab names and select options follow the same rule as fields. A button says the action it performs.

Pass: every button, tab and option on a page starts with a capital and has no other capital except proper nouns and acronyms.

Tabs on an activity list.

Do: Pipedrive names its tabs To-do, Overdue, Today, Tomorrow, This week and Next week.
Image: /ux/sources/pipedrive-activities-tabs.webp

Don't: The same tabs as This Week and Next Week.

Replace this: Create Project
With this: Create project

### Rename existing names in one pass

Our live bases still use Title Case: 413 multi-word field names against 5 in sentence case. A new name follows this rule from today. An existing name changes in a single rename pass, which waits on the user's decision. Until then, the examples in the interface skill and its validator's detail-name check also carry Title Case.

Pass: every name created after 2026-10-02 is in sentence case, and no existing field has been renamed on its own outside the pass.

## Research

The rule is copied from three CRMs: folk, Attio and Pipedrive all label their fields in sentence case. What the reader sees is the label, so capitals that come from styling still count as capitals. The folk people list shows `Job title` and `My last interaction`, and the Attio companies list shows `Last interaction` and `Connection strength`.

The Microsoft Writing Style Guide uses sentence-style capitalization by default. Intuit's Actions page says sentence case is easier to read, and its Do and Don't pair for buttons, "Create project" against "Click here", names the action the button performs.

### Sources

- [folk people list](https://mobbin.com/screens/5bdd96ea-2d5f-453c-8363-586c5733f071)
- [Attio companies list](https://mobbin.com/screens/4087fbe2-d9dc-4097-ad39-f8501c937e70)
- [Pipedrive activities, time-bucket tabs](https://mobbin.com/screens/84f0062e-5138-41f9-8d99-cceeb5dce13c)
- [Microsoft Writing Style Guide, top 10 tips](https://learn.microsoft.com/en-us/style-guide/top-10-tips-style-voice)
- [Intuit Content Design, Actions](https://contentdesign.intuit.com/product-and-ui/actions/)
- [Square items list, Title Case columns](https://mobbin.com/screens/1482987b-cedc-401e-b4cd-6e2666d2bbee)