What do the red part of a pathbuilder mean?

The red color marks the disambiguation point, see https://wiss-ki.eu/de/node/54 :)

Cheers!

Thank you!

@Knurg Now I run up the docker here. On the page /admin/config/wisski/pathbuilder/example_pathbuilder/edit?destination=/admin/config/wisski/pathbuilder, I still cannot figure out why the ecrm:E36_Visual_Item sometimes is as disambiguator and sometimes not, as the screenshot below:

I think in this example the disambiguation has no function and is there of legacy reasons. Disambiguation is used if you want to identify a entity via a property or entity reference routines to reuse it or link to an existing one.
If you have the field "birthplace" with the path "Person -> born -> Birth -> take place -> Place -> identified by -> Appellation" and one person is born in Chongqing and another person, too and you want to reuse the place entity called Chongqing you disambiguate in Place, then if you fill in the field birthplace "Chongqing" the entity is reused. If you want not only create new entities by one field, but have the whole form, you use Entity reference. But we have a mattermost by the way: https://chat.wiss-ki.eu If you have more support issues, you may want to join the channel https://chat.wiss-ki.eu/wisski/channels/how-to.