Documentation Standards

Documentation Standards

In order to help the reader as much as possible and to create code examples that look and feel familiar, you should follow these standards.


  • The following characters are chosen for different heading levels: level 1 is =, level 2 -, level 3 ~, level 4 . and level 5 ";
  • Each line should break approximately after the first word that crosses the 72nd character (so most lines end up being 72-78 characters);
  • The :: shorthand is preferred over .. code-block:: php to begin a PHP code block (read the Sphinx documentation to see when you should use the shorthand);
  • Inline hyperlinks are not used. Separate the link and their target definition, which you add on the bottom of the page;
  • Inline markup should be closed on the same line as the open-string;



When you are working on the docs, you should follow the
`Documentation`_ standards.

Level 2

A PHP example would be::

    echo 'Hello World';

Level 3

.. code-block:: php

    echo 'You cannot use the :: shortcut here';

.. _`Documentation`:

Code Examples

  • The code follows the Coding Standards as well as the Twig Coding Standards;
  • To avoid horizontal scrolling on code blocks, we prefer to break a line correctly if it crosses the 85th character;
  • When you fold one or more lines of code, place ... in a comment at the point of the fold. These comments are: // ... (php), # ... (yaml/bash), {# ... #} (twig), <!-- ... --> (xml/html), ; ... (ini), ... (text);
  • When you fold a part of a line, e.g. a variable value, put ... (without comment) at the place of the fold;
  • Description of the folded code: (optional) If you fold several lines: the description of the fold can be placed after the ... If you fold only part of a line: the description can be placed before the line;
  • If useful to the reader, a PHP code example should start with the namespace declaration;
  • When referencing classes, be sure to show the use statements at the top of your code block. You don’t need to show all use statements in every example, just show what is actually being used in the code block;
  • If useful, a codeblock should begin with a comment containing the filename of the file in the code block. Don’t place a blank line after this comment, unless the next line is also a comment;
  • You should put a $ in front of every bash line.


Configuration examples should show all supported formats using configuration blocks. The supported formats (and their orders) are:

  • Configuration (including services and routing): YAML, XML, PHP
  • Validation: YAML, Annotations, XML, PHP
  • Doctrine Mapping: Annotations, YAML, XML, PHP
  • Translation: XML, YAML, PHP


// src/Foo/Bar.php
namespace Foo;

use Acme\Demo\Cat;
// ...

class Bar
    // ...

    public function foo($bar)
        // set foo with a value of bar
        $foo = ...;

        $cat = new Cat($foo);

        // ... check if $bar has the correct value

        return $cat->baz($bar, ...);


In YAML you should put a space after { and before } (e.g. { _controller: ... }), but this should not be done in Twig (e.g. {'hello' : 'value'}).

Files and Directories

  • When referencing directories, always add a trailing slash to avoid confusions with regular files (e.g. “execute the console script located at the app/ directory”).

  • When referencing file extensions explicitly, you should include a leading dot for every extension (e.g. “XML files use the .xml extension”).

  • When you list a Framework file/directory hierarchy, use your-project/ as the top level directory. E.g.

    ├─ app/
    ├─ src/
    ├─ vendor/
    └─ ...

English Language Standards

  • English Dialect: use the United States English dialect, commonly called American English.

  • Section titles: use a variant of the title case, where the first word is always capitalized and all other words are capitalized, except for the closed-class words (read Wikipedia article about headings and titles).

    E.g.: The Vitamins are in my Fresh California Raisins

  • Punctuation: avoid the use of Serial (Oxford) Commas;

  • Pronouns: avoid the use of nosism and always use you instead of we. (i.e. avoid the first person point of view: use the second instead);

  • Gender-neutral language: when referencing a hypothetical person, such as “a user with a session cookie”, use gender-neutral pronouns (they/their/them). For example, instead of: * he or she, use they * him or her, use them * his or her, use their * his or hers, use theirs * himself or herself, use themselves