Is "RelationshipType" DESCRIBES limited to describing relationships between SPDX documents and software packages?

Here is some background on the question;

In consideration that a Usage Profile informs the terms of use of deliverables from a supplier downstream, the issue is how to express the relationship between a profile and software packages.

Here, if the 3.0 model Relationship follows the v2.3 specification, using DESCRIBES looks to have less impact. However, DESCRIBES is defined to indicate the relationship between an SPDX Document and software packages it covers [1], and an SPDX Document has only one as itself [2]. In that case, a profile should be configured as its SPDX Document as its own. Also, CONTAINS is better used only for evaluating the relationship between software packages for machine readability, so it is unsuitable for expressing the relationship between a profile and software packages.

If the answer to the question is YES, we should find another way.

Considering to evaluate the relationship between SPDX elements only with "relationshipType" concisely and to indicate the relationship between a profile and software packages clearly, we may introduce a new identifier for a profile and a new "RelationshipType" to show the relationship between a profile and software packages.

The following is just my opinion.

New SPDX identifier field
  Profile SPDX identifier field
  Format: "SPDXRef-PROFILE-"[idstring]
Example:
  SPDXID: SPDXRef-PROFILE-USAGE-1

New RelationshipType
  RelationshipType: COVERS
Example:
  "relationships": [
    {
      "relationshipType": "COVERS",
      "relatedSpdxElement": "SPDXRef-PROFILE-USAGE-1",
      "spdxElementId": "SPDXRef-1"
    }
　],

Any comments are really welcome!


[1] https://spdx.github.io/spdx-spec/v2.3/relationships-between-SPDX-elements/
[2] https://spdx.github.io/spdx-spec/v2.3/document-creation-information/#63-spdx-identifier-field