When defining pipeline resource, you are forced to specify the pipeline name and full path if any:

resources:
  pipelines:
  - pipeline: my
    source: 'MyFolder\My Pipeline'

This introduces a problem when pipeline is renamed/moved. One of the possible solutions is to allow specifying pipeline resource by id:

resources:
  pipelines:
  - pipeline: my
    sourceId: 123

Originally submitted https://developercommunity.visualstudio.com/t/Allow-specifying-pipeline-id-in-pipeline/1698296 three and a half years ago.