General Information

The authoritative style guide for writing official text for TYPO3 is The TYPO3 Writing Style Guide on typo3.org.

This section aims to add some additional explanations and more examples for rules already defined in the style guide. It also explains how to apply the rules in the documentation (e.g. format with reST).

Since the English language is not always specific and there may be more than one correct spelling for some words, we have added a Spelling & Preferred Terms Reference. If something is not mentioned here specifically, use correct spelling in English language or rather American (US) language. Refer to the resources, which the style guide suggests, or use Merriam Webster (https://m-w.com) as last resort. If in doubt, ask in Slack channel #typo3-documentation (see Help & Support) or contact the Content Group.

Rules for Titles & Section Headers

Basic rules (read in this order, use the first rule that applies and skip the rest):

  1. Exceptions: Words with special spelling like TYPO3, TypoScript, PHP, stdWrap etc. are written the way they are commonly written (see Exceptions: Specific TYPO3 Spellings, Acronyms). The same goes for class names, functions, database tables, database fields, configuration options etc. that are taken from the source code: They are written the way they are written in the source (see Exceptions: Words Taken From Source Code).
  2. The first and the last word of a title is always capitalized.
  3. Capitalize all words with 4 or more letters.
  4. Capitalize all important words (nouns, pronouns, adjectives, verbs, adverbs), for example “Is”, “Are”, “Has”.
  5. Lowercase articles (e.g. a, an, the) prepositions (e.g. in) and conjunctions (e.g. and, or) with fewer than 4 letters.

Capitalize means: The first letter of a word is a capital letter. Example: England is capitalized, the is not.


You can use the tool https://capitalizemytitle.com/ to check the title. Choose “AP” and “Title Case” for correct spelling in title. The result may slightly deviate from our rules for the exceptions (e.g. TYPO3). For a spelling reference, see Title Spelling Reference on this page.

The rules for title case are based on the TYPO3 Content Style Guide:


  • TYPO3 is always spelled TYPO3 (rule #1): “TYPO3 Is Always Spelled TYPO3”, “stdWrap”, “TypoScript”, “Programming With PHP”, “insert()”
  • The first word is always capitalized (see rule #2), so in is capitalized here: “In the End”
  • With is a preposition with 4 letters, so it must be capitalized (rule #3): “Install With Composer”
  • Is is a verb. Though it is short, do capitalize it (rule #4), as in “This Is the End”
  • In is a preposition with fewer than 4 letters, so first letter is lowercase (rule #5): “Rules in the Style Guide”


This applies to all headers on a page, not just the top level header (title).

In reST, headers are created by underlining / overlining with (====, ----, etc.) as described in Headlines and Sections:

This Is the Title

This Is the Subheader

Rules for Buttons

The same rules as in the title apply to buttons: Style Guide: Buttons

Rules for Referring to GUI Elements

If the text refers to terms used in the GUI (e.g. a clickpath for selecting something from the menu is described), the spelling used in the GUI should be used, e.g. “File > Open” or “click on “ADMIN TOOLS > Extensions”.

See Referring to GUI Elements for information about how to use reST markup for this.

Rules for Plain Text

As already mentioned: If the text is used in titles, subheaders, anchor text or a text is referring to GUI elements, use the correct spelling for that.

For anything else (plain text) common rules of the English language are applied.

Rules for Compound Words

Compound words (or compounds) are words that have been glued together from one or more separate words to create a new term with a new meaning as in backyard (back and yard) or New Age (new and age).

But how should they be spelled? Backend, back-end or back end? Site package or sitepackage?

All these spellings for backend are currently correct spellings (at least according to some sources.


In the TYPO3 context we have defined backend to be the preferred spelling, as well as sitepackage.

If a spelling has been explicitly defined in the Spelling & Preferred Terms Reference, please use that spelling.

How can you decide for yourself in other edge cases?


If in doubt, use what is commonly used in the documentation. If you see inconsistencies between documentation and English dictionaries or within the documentation, raise the issue in Slack.

Capitalization Rules (plain text)

  1. If a word has special spelling, e.g. a special TYPO3 word like TypoScript or an acronym like PHP, this spelling is applied.
  2. Proper nouns and brand names are capitalized, e.g. Docker.
  3. Most other words begin with a lowercase letter.

There are some edge cases and some terms are not spelled consistently throughout various resources. Often it also depends on the context. Capitalization may change over the course of time, for example see The Associated Press style guide will no longer capitalize ‘internet’. In other texts, “internet” is still capitalized.

For this reason we have put together a spelling reference to list some common terms that may be difficult to spell or that are spelled differently in the TYPO3 context.

Exceptions: Specific TYPO3 Spellings

There are some specific TYPO3 spellings like TypoScript, TSconfig, stdWrap, ViewHelper, TYPO3, etc. These should be used! See Spelling & Preferred Terms Reference for more examples.

Exceptions: Words Taken From Source Code

If you are using class names, function names, databases tables or fields, configuration options etc, use the spelling that is used in the source code.



Often acronyms are written with capital letters only. If terms are commonly spelled that way, this is how we spell them as well, for example HTML, CMS, PHP or LTS.

Proper Names, Brand Names

General rules of the English language apply here:

If proper names or brand names (e.g. Coca-Cola) are used in normal text (not headlines), they are capitalized.

These can be countries, names of people, corporations or brand names.


  • “This manual is designed to be readable by someone with basic UNIX command-line skills, but no previous knowledge of Git.”: Git is capitalized, because it is a brand name (quote from Git User Manual)
  • Wikipedia
  • Europe

Tools With Executables

Some tools have a program, which you can run. For example, Git has the command line tool git. When the documentation explicitly refers to the command git, its appropriate spelling is used, which is lowercase. In all other cases, we use capital spelling for Git, because it applies to the rules for Proper Names, Brand Names.

The same goes for Docker, Composer, etc.

Spelling & Preferred Terms Reference

The spelling here is how the terms will be used in normal text (not headlines).

backend (noun)

Usually not capitalized. This is not specific to TYPO3. Fluid is capitalized, like Docker (see Proper Names, Brand Names). Backend is a general thing, like any backend, any extension, any plugin or any car and not a 1953 Chevy Corvette.

Example: “when you log in to the backend …”

Note: Outside of the TYPO3 context, you will also encounter spellings like back-end or back end. These are not wrong, but in the context of TYPO3, we try to use consistent spelling, so stick to backend.

code sprint
Commonly written in lowercase. See Wikipedia: Hackathon
(the TYPO3) Core
Example: “The TYPO3 Core comes with a number of icons that may be used in your extension.”
Adhering to Docker rule set. Use Composer unless you explicitly mean the command composer.
(the TYPO3) Core Team
(the TYPO3) Documentation Team
Capitalized, unless it means any documentation team.
The product Docker is a brand name and therefore capitalized, so use that unless you explicitly mean the command docker (see Use the Docker command line).
Edit me on GitHub workflow
Use this to describe the workflow which involves editing on GitHub as opposed to “local editing and rendering with Docker”.
Capitalized. Adhering to the rule set of Proper Names, Brand Names.

See description for backend for an explanation of why we use lowercase.


  • “When you create the documentation for your extension, make sure …”
  • “… includes all TYPO3 extensions that are uploaded to TER”
Extension Manager
Capitalized. Example: “Use the Extension Manager to activate an extension.”
Capitalized. The rule set of Proper Names, Brand Names.
Usually not capitalized. See backend for an explanation.
The same applies as for Docker. Use Git unless you explicitly mean the command line command git.
Exception: This is the official spelling.
Introduction Package
Example: “The official TYPO3 Introduction Package is a great place to start”
Local editing and rendering with Docker
is used to describe the workflow of editing locally.
quick start
Of course, if used as a title, it will be spelled Quick Start!
This is the official spelling. Alternate word: reST, but this may be confused with REST(ful). We commonly use reST within this document, because it is shorter and we assume you know we are not talking about REST here, but elsewhere, reStructuredText should be preferred.
In the context of a TYPO3 sitepackage, a TYPO3 sitepackage extension or the sitepackage builder, we use the spelling sitepackage and not site package.
system extension
“system extension” is commonly used to describe an extension shipped with the core and located in the directory sysext in the file system. The alternate term “core extension” is discouraged (see Issue on GitHub).
is an acronym.
third party extension
Not a system extension maintained in the core, an extension publicly available. It is preferred to use “third party extension” and not “3rd party extension” (see Issue on GitHub for discussion).
TYPO3 exception. Note the lowercase “c” after TS! Spelling TSConfig is sometimes used, but it should be TSconfig!
TYPO3 exception: TYPO3 is always spelled TYPO3.
TYPO3 exception
TYPO3 exception

See also Issue on GitHub for terms pending a decision.

Title Spelling Reference

This is a list of words and how they should be used in a title.

Most words in a title are capitalized. Exceptions are articles, prepositions and conjunctions with less than 4 letters and a few exceptions like acronyms (all caps) or words that use capital letters within a word (e.g. stdWrap, TypoScript).

See rules for title case.

These are only some examples, more examples for lowercase spelling, see TYPO3 Content Style Guide.

Even if a word is lowercased in this list, it is always capitalized if used as first or last word in title!

Rule #5: Article with less than 4 letters (lowercase)
Rule #3 and #4: 4 letters or more and adverb
Rule #5: Article with less than 4 letters (lowercase)
Rule #5: Conjunction with less than 4 letters (lowercase)
Rule #5: Conjunction with less than 4 letters (lowercase)
Rule #5: Preposition with less than 4 letters (lowercase)
Rule #4: Pronoun
Rule #5: Preposition with less than 4 letters (lowercase)
Rule #4: Verb
Rule #4: Pronoun
Rule #4: Pronoun
Rule #5: Conjunction with less than 4 letters (lowercase)
Rule #1: Exception
Rule #4: Pronoun
Rule #1: Exception
Rule #5: Article with less than 4 letters (lowercase)
Rule #3: 4 letters or more
Rule #1: Exception: TYPO3 is always spelled TYPO3
Rule #1: Exception
Rule #3: 4 letters or more. Capitalized even though preposition.
Rule #3: 4 letters or more. Capitalized even though preposition.
Rule #3: 4 letters or more. Capitalized even though preposition.

Used Resources

In addition to the TYPO3 Content Style Guide, some other resources have been used:


Compound words: