Collaboration meaning: As we know

As we know, we only can 'Publish' in collaboration branch and changes are being pushed to to "adf_publish" branch by default. By default, the collaboration branch is named main. If you want team work, you need to create several branches. Working on the own branch, we can validate and debug the pipeline to make sure everything is ok. Then click save all, it will commit on the own branch. If we want publish, we need to creat a pull request to the main branch. 4.After merged to the main branch ... I'm designing an app which needs to have some collaboration functionality. So 1 to many users can edit certain attributes of an event they plan together. e.g. the main-admin can change the title, picture etc. while all admin-users could change the date for example. The collaboration branch is different also from the others for being able to call ADF pipelines from logic apps or anything else external to ADF (after using the publish button). When creating a Collaboration Diagram in Doxygen that specifies the connections between Doxygen groups, what is the meaning of a purple dashed line without an arrow?