Purpose

ClearlyDefined licensing data forms the core understanding required to meet FOSS licensing obligations. This data includes:

declared and discovered license information
attribution information
source location information
facet information

This document sets out the minimum processes the ClearlyDefined community follows to curate each class of data.

License information

There are five possible license property values on a definition element:

A valid SPDX license expression.
The string NOASSERTION. This indicates that license-like data is found, but that ClearlyDefined cannot identify an SPDX-identified license.
The string NONE. This indicates that a human confirmed that there is no license information in the file.
The string OTHER. This indicates that a human confirmed that there is license information in the file but that the license is not an SPDX-identified license.
No value. This indicates that automated tooling did not find license-like data in the file.

ClearlyDefined will follow the SPDX Matching Guidelines. If a license fails to meet the requirements of the SPDX Matching Guidelines, the license will be curated as OTHER.

The Difference between “Source components” and “Package components”

The process below differs for components depending on whether they are “source” or “package” components. A “source” package is the component in the preferred form of editing or building, like a Git repository. A “package” component is a component in its functional form that is intended to be used without further editing or building, like would be installed by a package manager.

For some package types such as Maven and Debian, both the “package” and “source” components are created simultaneously under their own respective ClearlyDefined definitions and linked together.

Both may contain equally valuable information and should be reviewed and curated together. For Maven, the definition containing the source has the type “sourcearchive”, while Debian has “debsrc”.

The Difference between Declared and Discovered licenses

The ClearlyDefined definition for a component has two types of license information: declared and discovered.

The declared license for a component is what the component explicitly calls out, formally or through convention, as the overall license. This might be a LICENSE or README file at the root of a repo or the value of a LICENSE property in a package’s metadata such as packgage.json or pom.xml.
The discovered licenses in a component’s definition are the other licenses found in the files of the component or sub-components of the overall project. For example, a source file or sub-directory might have a header comment indicating an SPDX license id, or a sub-directory might be under a different license.

In other words, the declared license is what normal developers would understand the component producers intended the overall project license to be. The discovered licenses represent what other licenses are found in the component.

Source components

Source component declared license

To evaluate the declared license info for a source component, use the following steps:

Determine the canonical names and locations for the declared licenses in the ecosystem at hand. These names and locations are listed in the source canonical locations section below.
Look to see whether there is license information in the relevant canonical locations for that ecosystem.
If there is, evaluate that canonical license information against the current declared license definition in ClearlyDefined.

Source component discovered licenses

To evaluate the discovered licenses for a source component, use the following steps:

Identify all files in the repository labeled as NOASSERTION or with an SPDX expression containing AND or OR.
Review each such file to determine whether there is an SPDX-identified license. There are three cases:
1. If there are SPDX-identified license(s) in the file, use the SPDX license expression to capture those licenses.
2. If there is no license in the file, code NONE.
3. If there is a license but that license does not have an SPDX identifier, code as OTHER.

Package components

Although a package component can have a different license than the underlying source used to create that package, most license obligations from the source flow through to the package. Thus, package definitions data must incorporate the definition data from the source.

Package components declared license

To evaluate the declared license info for a package component, use the following steps:

Determine the canonical names and locations for the declared licenses in the ecosystem at hand. These names and locations for common ecosystems are listed in Appendix A.
Look to see whether there is license information in the relevant canonical locations for that ecosystem.
If there is, evaluate that canonical license information against the current declared license definition in ClearlyDefined.

Package components discovered license

To evaluate the discovered licenses for a package component, use the following steps:

Identify all files in the repository labeled as NOASSERTION or with an SPDX expression containing AND or OR.
Review each such file to determine whether there is an SPDX-identified license. There are three cases:
1. If there is/are SPDX-identified license(s) in the file, use the SPDX license expression to capture those licenses.
2. If there is no license in the file, code NONE.
3. If there is a license, but that license does not have an SPDX identifier, code OTHER.
Follow the above steps for the source component definition that corresponds to the package component definition. If you see </> next to the magnifying glass symbol, you can pull it up automatically.

Canonical locations for the declared license for source definitions

When curating the declared license for a source code repository, look in the canonical locations listed below.

Source repository. Look to see if a license file (e.g. LICENSE, COPYING) is included in the specific commit or version you are curating. Sometimes the license is found on the README. There may be more than one declared license. If there is not any license information at the specific commit or version level, check the master branch.
File Headers. If there is not a declared license anywhere in the repository, look to see if there is any license information in the source code file header comments. Look at multiple files to determine if they are under different licenses. You can also try using a search function to find any mention of ‘license,’ for example.

Canonical locations for the declared license for package definitions

When curating the declared license for a package, look in all the canonical locations listed below (1-3). Appendix A has canonical locations for common package ecosystems.

If the canonical locations do not match (e.g., the license file states Apache-2.0 and the metadata states MIT), contact the author/publisher. If you do not receive a response after 7 days, prioritize curating the declared license in the order listed below.

Package files. Look to see if a license file (e.g. LICENSE, COPYING) is included in the package file contents. Sometimes there is license information on a README.
Package metadata. Look to see if the target component metadata includes any license info, such as a license identifier or license file URL.
Source repository. Follow the canonical locations for source definitions, above. Also look for package manifest files (e.g. package.json, setup.py).

File level curations

In ClearlyDefined, you can curate license and copyright information at the file level in the “Files” section of the definition. For further information, also see the Attribution information section below.

License information to include. When curating license information for an individual file, string together all the licenses found on the file with an “AND,” unless otherwise specified. For example, a file has a code comment at the top saying the component is MIT. Further down the file is a comment saying a portion of the file is based on an Apache-2.0 licensed project. When curating that file, you would curate “MIT AND Apache-2.0.”
License information to ignore. Occasionally you may see a reference to a license that is not meant to apply to the file. For example, a code comment saying the data looked at GPL licensed projects, would not result in a GPL license curation.
Copyright information to include. When curating the copyright information for an individual file, add any copyright statements found on the file.
Copyright information to ignore. Some licenses include a copyright statement for the license text itself. A copyright curation would not include the license’s copyright statement.

Troubleshooting

We always prefer a reference to a version control system, but if you’re unable to find that, other public references are okay.

Target component package metadata gives a URL that points to a volatile location (e.g. a webpage or the master branch of a git repository).
- Look for evidence of the license at the time the target component was published.
Target component package metadata points to a license URL in source repository, but the link is broken.
- Ignore the link specifics and look for license information in other canonical locations in that source repository.
Target component package metadata does not have a license URL or license information. There exists a related version (newer or older) of the package that does have license information.
- Use the related component’s license data, favoring for newer version if possible to discern.
Target component has no project/source location and does not have any license information, but does declare a license in the copyright field (e.g., <Copyright MIT>)
- Use the declared license in the copyright field
Target component is using multiple licenses.
- Use an SPDX expression to indicate multiple licenses, using AND, OR, or WITH (see https://spdx.org/licenses/).
Curate the declared license as NONE when the component verifiably and intentionally has no license.
Curate the declared license as OTHER when the license is a proprietary license, such as an End-User-License-Agreement.
Curate the declared license as ‘OTHER’ when there is a reference saying the target component is in the public domain.
Target component includes a license file and a separate PATENTS file that grants additional patent rights. Curate the declared field with the license and add “AND OTHER”.
Target component license information is limited to a non-SPDX license identifier that may not be version specific:
- If the only license information is “BSD,” code the license as “BSD-3-Clause.” Note - https://opensource.org/licenses/bsd-license.php is not a license version specific link.
- For L/GPL licensed packages, look in the ReadMe, package manifest, and source code files to determine if it is “GPL-#-only” or “GPL-#-or-later.” (Do not use the deprecated SPDX license identifiers – e.g. GPL-2.0+).
- If the only license information is “GPL,” with no COPYING license file, code the license as “GPL-1.0-or-later.” Note - http://www.gnu.org/licenses/gpl.txt is not a license version specific link.
- If the only license information is “LGPL” with no COPYING license file, code the license as “LGPL-2.0-or later.”
Target component’s license file states it is a “fork of,” “implementation of,” or “is derived from” another project, and the original project is under a different license from the target component. In this case, the license of the original project is a “discovered” license. If the original project license is not already included as a “discovered” license, look for an appropriate file in the “Files” section of ClearlyDefined to add the license information. For example, a NuGet package points to a license that states the project is MIT and is a fork of a project that is Apache-2.0 and the Apache-2.0 license is not showing up as a “discovered” license. Here, you can curate the nuspec file as “MIT AND Apache-2.0.”

Attribution Information

Process. The curator should look at each copyright statement. Copyright statements should be removed only when it is abundantly clear that the string is not a copyright statement and it was surfaced by the scanners in error.
Rationale. Because copyright statements take a wide variety of forms, sometimes including typos or other inconsistencies, it is not the ClearlyDefined curator’s role to guess the intent of the author or contributor to the package and so the Copyright statement should remain unmodified.

Source Location Information

[TODO]

Appendix A - Package ecosystems

When evaluating license information, always look in the version specific canonical location that corresponds to the version of the target component package.

Maven

	Canonical Location
Package files	Look in the -sources.jar.
Package metadata	Look on the .pom file.
Source repository	Look on the .pom file for a URL to the source repository.

NPM

	Canonical Location
Package files	Look in the “Files” section on the ClearlyDefined definition.
Package metadata	Look on the package.json in the “Files” section on the ClearlyDefined definition. Alternatively, you can look on http://registry.npmjs.com/ (use this format: `http://registry.npmjs.com/[package name]/[version number]`). Note: the license information on npmjs.com displays the most current package license for all versions. Unless you are evaluating the license for the most current package, you will want to use a version specific canonical location.
Source repository	The “Source” field on the ClearlyDefined definition may link to a GitHub commit. Alternatively, you can look on the registry or the package.json file for a URL to the source repository. The package on https://www.npmjs.com may also provide a link to the repository.

NuGet

	Canonical Location
Package files	Look in the “Files” section on the ClearlyDefined definition.
Package metadata	Look on https://www.nuget.org/.
Source repository	The “Source” field on the ClearlyDefined definition may link to a GitHub commit. The package on https://www.nuget.org may also provide a link to the source repository.

PyPi

	Canonical Location
Package files	Look in the “Files” section on the ClearlyDefined definition. You can also click on “Download files” on https://pypi.org.
Package metadata	Look on https://pypi.org. Do not rely on the Statistics links. You can also look at the setup.py file in the “Files” section on the ClearlyDefined definition.
Source repository	The “Source” field on the ClearlyDefined definition may link to a GitHub commit. You can also click on “Homepage” under “Project links” on https://pypi.org/.

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