Documentation Guidelines

Document Software Setup

AboutCode documentation is built using Sphinx. See

AboutCode documentation is distributed using “Read the Docs”. See

Individual document files are in reStructuredText format. See

You create, build, and preview AboutCode documentation on your local machine.

You commit your updates to the AboutCode repository on GitHub, which triggers an automatic rebuild of

Clone AboutCode

To get started, create or identify a working directory on your local machine.

Open that directory and execute the following command in a terminal session:

git clone

That will create an /aboutcode directory in your working directory. Now you can install the dependencies in a virtualenv:

cd aboutcode
virtualenv -p /usr/bin/python3.6 docs-venv
source docs-venv/bin/activate

Now, the following prerequisites are installed

  • Sphinx

  • sphinx_rtd_theme (the format theme used by ReadTheDocs)

  • docs8 (style linter)

pip install Sphinx sphinx_rtd_theme doc8

Now you can build the HTML documents locally:

cd docs
make html

Assuming that your Sphinx installation was successful, Sphinx should build a local instance of the documentation .html files:

open build/html/index.html

In case this command did not work, for example on Ubuntu 18.04 you may get a message like “Couldn’t get a file descriptor referring to the console”, try:

see build/html/index.html

You now have a local build of the AboutCode documents.

Improve AboutCode Documents

Before you begin creating and modifying AboutCode documents, be sure that you understand the basics of reStructuredText as explained at

Ensure that you have the latest AboutCode files:

git pull
git status

Use your favorite text editor to create and modify .rst files to make your documentation improvements.

Review your work:

cd docs
make html
open build/html/index.html

AboutCode uses Travis-CI to test build status and check links, so run this script at your local system before creating a Pull Request.

cd docs

Share AboutCode Document Improvements

Follow standard git procedures to upload your new and modified files. The following commands are examples:

git status
git add source/index.rst
git add source/how-to-scan.rst
git status
git commit -m "New how-to document that explains how to scan"
git status
git push
git status

The AboutCode webhook with ReadTheDocs should rebuild the documentation after your Pull Request is Merged.

Refer the Pro Git Book available online for Git tutorials covering more complex topics on Branching, Merging, Rebasing etc.

Continuous Integration

The documentations are checked on every new commit through Travis-CI, so that common errors are avoided and documentation standards are enforced. Travis-CI presently checks for these 3 aspects of the documentation :

  1. Successful Builds (By using sphinx-build)

  2. No Broken Links (By Using link-check)

  3. Linting Errors (By Using Doc8)

So run these scripts at your local system before creating a Pull Request:

cd docs

Style Checks Using Doc8

How To Run Style Tests

In the project root, run the following command:

$ doc8 --max-line-length 100 docs/source/ --ignore D000

A sample output is:

docs/source/scancode-toolkit/misc/licence_policy_plugin.rst:37: D002 Trailing whitespace
docs/source/scancode-toolkit/misc/faq.rst:45: D003 Tabulation used for indentation
docs/source/scancode-toolkit/misc/faq.rst:9: D001 Line too long
docs/source/scancode-toolkit/misc/support.rst:6: D005 No newline at end of file
Total files scanned = 34
Total files ignored = 0
Total accumulated errors = 326
Detailed error counts:
    - CheckCarriageReturn = 0
    - CheckIndentationNoTab = 75
    - CheckMaxLineLength = 190
    - CheckNewlineEndOfFile = 13
    - CheckTrailingWhitespace = 47
    - CheckValidity = 1

Now fix the errors and run again till there isn’t any style error in the documentation.

What is Checked?

PyCQA is an Organization for code quality tools (and plugins) for the Python programming language. Doc8 is a sub-project of the same Organization. Refer this README for more details.

What is checked:

  • invalid rst format - D000

  • lines should not be longer than 100 characters - D001

    • RST exception: line with no whitespace except in the beginning

    • RST exception: lines with http or https URLs

    • RST exception: literal blocks

    • RST exception: rst target directives

  • no trailing whitespace - D002

  • no tabulation for indentation - D003

  • no carriage returns (use UNIX newlines) - D004

  • no newline at end of file - D005


Aboutcode documentation uses Intersphinx to create links to other Sphinx Documentations, to maintain links to other Aboutcode Projects.

To link sections in the same documentation, standart reST labels are used. Refer Cross-Referencing for more information.

For example:

.. _my-reference-label:

Section to cross-reference

This is the text of the section.

It refers to the section itself, see :ref:`my-reference-label`.

Now, using Intersphinx, you can create these labels in one Sphinx Documentation and then referance these labels from another Sphinx Documentation, hosted in different locations.

You just have to add the following in the file for your Sphinx Documentation, where you want to add the links:

extensions = [

intersphinx_mapping = {'scancode-toolkit': ('', None)}

To show all Intersphinx links and their targets of an Intersphinx mapping file, run:

python -msphinx.ext.intersphinx


python -msphinx.ext.intersphinx will give error.

This enables you to create links to the scancode-toolkit Documentation in your own Documentation, where you modified the configuration file. Links can be added like this:

For more details refer :ref:`scancode-toolkit:doc_style_guide`.

You can also not use the scancode-toolkit label assigned to all links from, if you don’t have a label having the same name in your Sphinx Documentation. Example:

For more details refer :ref:`doc_style_guide`.

If you have a label in your documentation which is also present in the documentation linked by Intersphinx, and you link to that label, it will create a link to the local label.

For more information, refer this tutorial named Using Intersphinx.

Extra Style Checks

  1. Headings

    (Refer) Normally, there are no heading levels assigned to certain characters as the structure is determined from the succession of headings. However, this convention is used in Python’s Style Guide for documenting which you may follow:

    # with overline, for parts

    • with overline, for chapters

    =, for sections

    -, for subsections

    ^, for sub-subsections

    “, for paragraphs

  2. Heading Underlines

    Do not use underlines that are longer/shorter than the title headline itself. As in:

Correct :

Extra Style Checks

Incorrect :

Extra Style Checks


Underlines shorter than the Title text generates Errors on sphinx-build.

  1. Internal Links

    Using :ref: is advised over standard reStructuredText links to sections (like `Section title`_) because it works across files, when section headings are changed, will raise warnings if incorrect, and works for all builders that support cross-references. However, external links are created by using the standard `Section title`_ method.

  2. Eliminate Redundancy

    If a section/file has to be repeated somewhere else, do not write the exact same section/file twice. Use .. include: ../README.rst instead. Here, ../ refers to the documentation root, so file location can be used accordingly. This enables us to link documents from other upstream folders.

  3. Using :ref: only when necessary

    Use :ref: to create internal links only when needed, i.e. it is referenced somewhere. Do not create references for all the sections and then only reference some of them, because this created unnecessary references. This also generates ERROR in restructuredtext-lint.

  4. Spelling

    You should check for spelling errors before you push changes. Aspell is a GNU project Command Line tool you can use for this purpose. Download and install Aspell, then execute aspell check <file-name> for all the files changed. Be careful about not changing commands or other stuff as Aspell gives prompts for a lot of them. Also delete the temporary .bak files generated. Refer the manual for more information on how to use.

  5. Notes and Warning Snippets

    Every Note and Warning sections are to be kept in rst_snippets/note_snippets/ and rst_snippets/warning_snippets/ and then included to eliminate redundancy, as these are frequently used in multiple files.

Converting from Markdown

If you want to convert a .md file to a .rst file, this tool does it pretty well. You’d still have to clean up and check for errors as this contains a lot of bugs. But this is definitely better than converting everything by yourself.

This will be helpful in converting GitHub wiki’s (Markdown Files) to reStructuredtext files for Sphinx/ReadTheDocs hosting.