If a license code is not defined in a package, but the package contains a license file, check other subjects of this package.

If the other subject contains an identical license file, copy the license code with the description The license file is identical to the {Subject} license file.

As an example nuget package CompareNETObjects

Spec contains only LICENSE_NET.txt:

<package>
  <metadata>
    <id>CompareNETObjects</id>
    <version>4.79.0</version>
    <license type="file">License.txt</license>
    <projectUrl>https://github.com/GregFinzer/Compare-Net-Objects</projectUrl>
  </metadata>
</package>

The project URL is GitHub repository GregFinzer/Compare-Net-Objects

• with MS-PL license
• the license content on GitHub is identical to the License.txt in the package

{
  "License": {
    "Code": "MS-PL",
  },
  "Licenses": [
    {
      "Subject": "package",
      "Code": "MS-PL",
      "HRef": "License.txt",
      "Description": "The license file is identical to the project license file."
    },
    {
      "Subject": "project",
      "Code": "MS-PL",
      "HRef": "https://github.com/GregFinzer/Compare-Net-Objects"
    }
  ]
}