A

a11y

Abbreviation for accessibility (11 letters between the A and Y), reserved for internal use or where space is a consideration, otherwise please avoid or explain on first use.

acronyms

Uppercase with no periods, unless they are specifically part of a brand name or the result spells out a different word.

add-on

See “Firefox Add-ons”; note that “add-ons” is always hyphenated, never “addons”. See also extension and theme, and see the Add-ons Terminology wiki entry for when to use which term.

address bar

Use this instead of location bar, awesome bar, or URL bar.

AMO

Our internal name for addons.mozilla.org; do not use in any user-facing communications.

B

Beta

See Firefox Beta.

buttons

Use buttons only to indicate a user action that updates the current screen or transmits information to the application (e.g., “Submit,” “Update Preferences”); see also “links”.

C

capitalization

Unless there is an entry stating otherwise, please capitalize the following: brands and products (Mozilla, Firefox, Test Pilot, etc.); features (Firefox Screenshots, etc.); acronyms (URL, etc.). URLs (mozilla.org, firefox.com, etc.) are lowercase.

channels

Our term for the various builds of our products; please avoid in user-facing communications.

customers

Do not use: we refer to “users” or “people.”

D

data

Treat data as a singular entity: data “is” sent, this data “is” available; not data “are” sent, these data “are” available. In general, avoid using data as a term when you can use the more helpful term information, or when you can be more specific about types of data, like browsing history, IP address or timestamp.

Do Not Track

Capitalized when referring to the setting in privacy preferences.

double-click

Hyphenated in all forms and uses.

E

email

One word, lowercase, no hyphen.

extension

A type of browser add-on; see “Firefox Extensions.” See also theme, and see the Add-ons Terminology wiki entry for when to use which term.

F

features

Individual product features are capitalized unless there is an entry stating otherwise.

Fennec

The internal code name for our Firefox for Android product; should not be used in user-facing communications.

Final Release

Our internal name for the mainstream versions of Firefox; do not use in user-facing communications.

Firefox Accounts

“Accounts” is capitalized when it follows Firefox, lowercase when on its own; it can be singular or plural as needed and is always localized.

Firefox Add-ons

Add-ons is capitalized when it follows Firefox, lowercase when on its own, though the O is always lowercase; it can be singular or plural as needed and is always localized. See also the Add-ons Terminology wiki entry.

Firefox Beta

Firefox Beta on the first mention, Beta on subsequent mentions, always capitalized.

Firefox Beta for mobile

“Beta for mobile” is also acceptable, but never “mobile Beta;” mobile is always lowercase.

Firefox browser

Use this to differentiate from another particular Firefox product (Firefox for Android, Firefox iOS, etc.); browser is always lowercase.

Firefox Developer Edition

Firefox Developer Edition on the first mention, Developer Edition on subsequent mentions, both words always capitalized.

Firefox for Android

Use this in most cases when referring to the mobile browser (see also “Firefox browser”); Android is always capitalized; never “Firefox Android,” “Firefox on Android” or any other variation.

Firefox for iOS

Use this in most cases when referring to the mobile browser (see also “Firefox browser”); never “Firefox iOS,” “Firefox on iOS” or any other variation.

Firefox for desktop

Use this to differentiate from the mobile browsers (see also “Firefox browser”); desktop is always lowercase; never “desktop Firefox” or “Firefox desktop.”

Firefox Extensions

Extensions is capitalized when it follows Firefox, lowercase when on its own; it can be singular or plural as needed and is always localized. See also the Add-ons Terminology wiki entry.

Firefox for mobile

Mobile is always lowercase; never “mobile Firefox” or “Firefox mobile.”

Firefox Nightly

Firefox Nightly on the first mention, Nightly on subsequent mentions, always capitalized.

Firefox Themes

Themes is capitalized when it follows Firefox, lowercase when on its own; it can be singular or plural as needed and is always localized; formerly “Firefox Personas.” See also the Add-ons Terminology wiki entry.

free

This one is tricky as it means both “without cost” and “without restrictions” in English, though there are separate words for these concepts in many other languages; please be very clear when using or avoid.

fullscreen

One word, lowercase, when referring to the view mode of the browser; use “entire screen,” “whole screen” or similar formulation in other cases.

G

gestures

For Firefox for Android, use the preferred Android terms touch, swipe, drag, pinch in, pinch out; learn more in the Google-maintained Material Design Style Guide.

For Firefox for iOS, use the preferred Apple terms tap, swipe, drag, pinch. View more in the Apple Human Interface Guidelines.

H

http://

“http://” should never appear before an URL in communications unless you are using it to demonstrate a complete hyperlink; see also www.

I

i18n

Abbreviation for internationalization (18 letters between the I and N), reserved for internal use or where space is a consideration, otherwise please avoid or explain on first use.

internet

Lowercase, unless the word “internet” is used to begin a sentence.

J

Join Mozilla

Refers specifically to the fundraising campaign and should not be used in other contexts; both words are capitalized and “Join” should never become “Joins,” “Joining” or any other form of the word.

L

l10n

Abbreviation for localization (10 letters between the L and N), reserved for internal use or where space is a consideration, otherwise please avoid or explain on first use.

learn more

Use to indicate a link to another screen or webpage; see also “more.”

left-click

Hyphenated in all forms and uses.

Use hyperlinked system text to indicate links to another screen or webpage see also “buttons.”

long-pressing

Hyphenate (for clarity) when describing this emerging term for this mobile touch gestures.

M

malware

Malware, like software, is an uncountable noun, which means it does not take a plural form and cannot be associated with a number; you should never refer to “a malware” or “three malwares.”

mobile

Lowercase, even if it follows Firefox; see also “Firefox for mobile.”

mobile device

In general, use this instead of “phone” or “tablet” unless you are purposely differentiating between the two. Use “mobile phone” only to distinguish from a “tablet,” otherwise, use “mobile device” mobile tablet redundant, do not use.

more

Use to indicate an expanding text area; see also “learn more.”

Mozilla

Make sure Mozilla is well established early or prominently in any writing or communications (Tabzilla satisfies this requirement, for example): either as part of a product name (Mozilla Firefox, Mozilla Webmaker, etc.) or on its own. Do not use any compound constructions (like Mozilla Firefox Marketplace); even though the Mozilla wordmark is lowercase. Mozilla should be capitalized in all other uses, unless as part of an URL (mozilla.org).

Mozilla Reps

Always two words, always capitalized.

Mozilla Space/Spaces

Official terms for a particular group of Mozilla offices around the world, which include open space for the community; current locations or those in the works include San Francisco, Toronto, London, Berlin, Tokyo, Auckland, Beijing, Paris, and Vancouver.

Mozilla Webmaker

Mozilla Webmaker on the first mention, Webmaker on subsequent mentions, always capitalized.

Mozillians

Refers to paid staff or volunteers of the Mozilla project; always uppercase unless part of an URL (mozillians.org).

MozSpace/MozSpaces

Informal terms for Mozilla Spaces reserved for internal use; do not use in any communications.

N

New Tab

Always capitalized.

New Window

Always capitalized.

non-profit

Though “nonprofit” is not incorrect, we prefer to use the hyphenated form.

numbers

Spell out as words from one to nine, use numerals 10 and up; spell out large numbers like thousand, million, etc. (see also “version numbers”).

O

open/open web

As the web is open by its very nature, there is no need to make the distinction; not a forbidden term, but avoid where possible; when specifically and intentionally referring to the Open Web movement, please capitalize.

options

Use “options” (instead of “settings”) for Firefox desktop on Windows, Firefox for Android and Firefox for iOS to conform with the platforms; see also, preferences.

P

people

Though we mostly refer to “users,” this is also acceptable, and either should be used instead of “customers.”

phone

See “mobile device.”

pop-up/pop up

Use pop-up for adjectives and nouns. Use pop up (space and no hyphen) for verbs.

possessives

Though you may run into cases where it’s impossible, please avoid using possessives with our brands or product names where you can; see also “plurals.”

plugin/plugins

Unless you’re talking about physically plugging something in, this should be one word, lowercase, when referring to things like Flash and QuickTime.

plurals

As with possessives, it is preferable not to pluralize our brands or product names; try to reword if you can.

preferences

Use preferences (instead of settings) for Firefox desktop on Mac to conform with the platform; see also, settings.

Private Browsing

Always capitalized.

Private Tab

Always capitalized.

Private Window

Always capitalized.

punctuation

R

release numbers

See “version numbers.”

ReMo

Our internal codename for Mozilla Reps; do not use in any user-facing communications.

right-click

Hyphenated in all forms and uses.

S

settings

Use “settings” (instead of “options” or “preferences”) for Firefox for mobile and Firefox Focus to conform with the platforms; see also, preferences.

Sign in

Use “sign in to Firefox” or “log in to Firefox” when you are instructing a user to enter site credentials. Do not use “sign into” or “log into”.

site

Site is an acceptable term to refer to a website; see also website.

SUMO

Our internal name for support.mozilla.org; do not use in any user-facing communications.

Start Page

Sync

Capitalized when talking about the feature in Firefox, lowercase when using it only as a descriptive term; avoid “Firefox Sync” where possible; variants are syncing, synced.

T

tablet

Use primarily to differentiate from a phone, otherwise use “mobile device” where possible.

theme

A type of browser add-on; see “Firefox Themes.” See also extension, and see the Add-ons Terminology wiki entry for when to use which term.

toolbar

Tracking Protection

Always capitalized. Do not make specific reference to advertising or ad-blocking when describing.

U

URL

All uppercase, no periods, but URLs themselves (mozilla.org, firefox.com, etc.) are lowercase.

users

Use this or “people” instead of “customers.”

V

version numbers

W

web

Lowercase on its own and as part of a compound construction (unless as noted). Capitalize if the word “web” begins a sentence.

webcam

One word, lowercase.

webcast

One word, lowercase.

WebExtensions

Used to describe the API an extension is built on; describes the technology, not an extension built on the technology; see also the WebExtensions wiki entry.

WebFWD

Please note the capitalization, unless dealing with a URL (webfwd.org).

webmaster

One word, lowercase.

Web Push

Capitalize when referring to the notification standard.

website

One word, lowercase; do not use “web site.”

Wi-Fi

Use Wi-Fi instead of wifi or WiFi.

www

Avoid using before URLs; modern browsers (and current users) will assume the www.