Copy rules

Introduction

These guidelines are for website content, campaigns and other communications intended for a general audience. If you’re looking for documentation guidelines, please visit the MDN Style Guide at the Mozilla Developer Network. If you’re looking for information about writing support articles, please see “How to write Knowledge Base articles” at Mozilla Support.

A–Z

(eh-to-zee)

a11y
our 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-ons
see “Firefox Add-ons”
AMO
our internal name for addons.mozilla.org; do not use in any user-facing communications
capitalization
unless there is an entry stating otherwise, please capitalize the following: brands and products (Mozilla, Firefox, Persona, Marketplace, etc.); features (Panorama, etc.); acronyms (URL, etc.). URLs themselves (mozilla.org, firefox.com, etc.) are lowercase
channels
our term for the various builds of Firefox (Nightly, Aurora, Beta, Final Release) and Thunderbird (Daily, Earlybird, Beta, Final Release); please avoid in user-facing communications
customers
do not use: we refer to “users” or “people”
double-click
hyphenated in all forms and uses
email
one word, lowercase, no hyphen
features
individual product features are capitalized, unless there is an entry stating otherwise
Fennec
internal code name for our mobile efforts as a whole, does not refer to any specific product and should not be used in outbound messaging
Final Release
our internal name for the mainstream releases of Firefox and Thunderbird; do not use in user-facing communications
Firefox
make sure to clearly specify whether you are talking about the Firefox family of products or one of those products (i.e. the Firefox browser) specifically; always capitalized unless appearing as part of a URL
Firefox Add-ons
add-ons is capitalized when it follows Firefox, lowercase when on its own; the O is always lowercase
Firefox Aurora
Firefox Aurora on first mention, Aurora on subsequent mentions, always capitalized
Firefox Beta
Firefox Beta on 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 the Firefox family of products or from another specific Firefox product (Firefox Marketplace, Firefox OS, etc.); browser is always lowercase
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 desktop
use this to differentiate from the mobile browser (see also “Firefox browser”); desktop is always lowercase; never “desktop Firefox” or “Firefox desktop”
Firefox for mobile
mobile is always lowercase; never “mobile Firefox” or “Firefox mobile”
Firefox Marketplace
Firefox Marketplace on first mention, Marketplace is acceptable on subsequent mentions, always capitalized; never “Mozilla Marketplace”
Firefox Nightly
Firefox Nightly on first mention, Nightly on subsequent mentions, always capitalized
Firefox OS
the official name of the project formerly known as Boot to Gecko (or B2G); always use the complete name; do not use “the Firefox OS” unless it is being treated as an adjective (e.g. the Firefox OS experience, the Firefox OS home screen, etc.)
Firefox Themes
themes is capitalized when it follows Firefox, lowercase when on its own; formerly "Firefox Personas"
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
FxOS
for internal usage, this is the official abbreviation of “Firefox OS,” but it should not be used in any external communications
gear
used to refer to any branded merchandise, be it Mozilla, Firefox or any of our other brands; please use instead of “swag” or “merchandise”
http://
this should never appear before a URL in communications unless there is a very good reason (though we can’t think of one off the tops of our heads)
i18n
our 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
always capitalized
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
l10n
our 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
left-click
hyphenated in all forms and uses
merch/merchandise
please use “gear” to refer to branded merchandise
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
mobile phone
use only to differentiate from a tablet, otherwise use “mobile device”
mobile tablet
redundant, do not use
Moz
we do not generally abbreviate the Mozilla name, unless otherwise noted in this guide; please avoid
MozCamp/MozCamps
regional gatherings of volunteer and paid staff that happen several times a year around the world (MozCamp Asia, MozCamp LatAm, etc.); note the capitalization
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, but 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 a URL (mozilla.org)
Mozilla Labs
though the Mozilla Labs wordmark is lowercase, always capitalize both words in regular text; Mozilla Labs on first mention, Labs on subsequent mentions
Mozilla Reps
always two words, always capitalized
Mozilla Space/Spaces
official terms for a specific 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 first mention, Webmaker on subsequent mentions, always capitalized
Mozillians
refers to paid or volunteer staff of the Mozilla project; always uppercase unless part of a URL (mozillians.org)
MozSpace/MozSpaces
informal terms for Mozilla Spaces reserved for internal use; do not use in any communications
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”)
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
Pancake
uppercase when referring to the tablet browsing experiment, lowercase when referring to the delicious breakfast food
people
though we mostly refer to “users,” this is also acceptable and either should be used instead of “customers”
Personas
use “Firefox Themes” instead; see that entry for usage details
phone
see “mobile phone”
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
product numbers
see “version numbers”
punctuation
see punctuation section below
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
SUMO
our internal name for support.mozilla.org; do not use in any user-facing communications
swag
please use “gear” to refer to branded merchandise
tablet
use primarily to differentiate from a phone, otherwise use “mobile device” where possible
Tabzilla
our internal name for the Mozilla universal tab that appears at the top of our sites; avoid using in user-facing communications or explain on first reference
themes
see “Firefox Themes”
Thunderbird
capitalized unless appearing as part of a URL
Thunderbird Beta
Thunderbird Beta on first mention, Beta on subsequent mentions (but only if it’s absolutely which product you’re referring to), always capitalized
Thunderbird Daily
Thunderbird Daily on first mention, Daily on subsequent mentions, always capitalized
Thunderbird Earlybird
Thunderbird Earlybird on first mention, Earlybird on subsequent mentions, always capitalized
URL
all uppercase, no periods, but URLs themselves (mozilla.org, firefox.com, etc.) are lowercase
users
use this or “people” instead of “customers”
version numbers
we no longer attach version numbers to releases of Firefox in any communications, though we do use them internally for tracking purposes
Web
always capitalized when on its own or part of a compound construction that doesn’t create a new word (Web page, Web feed, etc.); see individual entries for other uses
webcam
one word, lowercase
webcast
one word, lowercase
WebFWD
please note the capitalization, unless dealing with a URL (webfwd.org)
webmaster
one word, lowercase
website
all together now: one word, lowercase
www
avoid using (like the plague!) before URLs; it is not 1999 anymore

Punctuation

commas
we do not use serial commas (also called Oxford commas) in Mozilla communications
dashes
hyphens (-) are used to create a single idea out of two or more words and are always connected; en dashes (–) are used for ranges, like numbers and dates, and are also connected; em dashes (—) are used to set related, yet separate thoughts off from each other, either within a sentence or following it, and in either case they are not connected
exclamation points
it’s acceptable to use exclamation points, but don’t overdo it; they are not a replacement for creating genuine excitement in writing
quotation marks
punctuation generally goes inside quotation marks, including exclamation and question marks, unless the exclamation or question is part of the entire sentence, not just the portion contained in the quotation marks
slashes
if it’s in a URL, it’s a forward slash, people, not a backslash