Hello Wolfgang,

Neither usage of dependent_parameters is a keyword, in fact there is an error in the v1.0 spec related to custom records and the name field: https://github.com/common-workflow-language/common-workflow-language/issues/394

You can have as many dependent parameters as you want, just follow the pattern: custom record type with two or more fields.

Here's a real example that may help:

External definition of custom record type for re-use:

type: record
name: model
fields:
  - name: main
    type: File
  - name: prob_forward
    type: File
    label: Forward probability model
[…]

(From https://github.com/ProteinsWebTeam/ebi-metagenomics-cwl/blob/f8bb388/tools/FragGeneScan-model.yaml)

Import of the custom record type in the tool definition

requirements:
  SchemaDefRequirement:
    types:
      - $import: FragGeneScan-model.yaml
[…]

(From https://github.com/ProteinsWebTeam/ebi-metagenomics-cwl/blob/f8bb388/tools/FragGeneScan1_20.cwl#L21)

Use of the custom record type in that tool's inputs:

inputs:
  […]
  model: FragGeneScan-model.yaml#model

(From https://github.com/ProteinsWebTeam/ebi-metagenomics-cwl/blob/f8bb388/tools/FragGeneScan1_20.cwl#L51)

And likewise, using that tool in a workflow. First import the same custom type:

requirements:
 […]
 - class: SchemaDefRequirement
   types: 
    - $import: ../tools/FragGeneScan-model.yaml
    # other imports for other tool's custom types go here

(from https://github.com/ProteinsWebTeam/ebi-metagenomics-cwl/blob/f8bb388/workflows/emg-pipeline-v3.cwl#L9)

As needed reference it -- for example in the workflow level inputs:

inputs:
  […]
  fraggenescan_model: ../tools/FragGeneScan-model.yaml#model

(From https://github.com/ProteinsWebTeam/ebi-metagenomics-cwl/blob/f8bb388/workflows/emg-pipeline-v3.cwl#L18)

Thank you for your question, this part of the user guide is confusing and needs rewording. There is an open issue to remind the team to clarify and demonstrate this better: https://github.com/common-workflow-language/common-workflow-language/issues/438