While testing a change to an add-on that automatically creates node groups I noticed that the links in the group in the Geometry Node Editor window were dashed instead of solid. It seems to be related to the input group - so that the links proliferate through the tree - as they revert back to being continuous when not linked to the Node Group Input node as demonstrated in this animated image :
Iinitially thought I'd managed to manually create the node group without having the same problem but on re-trying it does seem to occur with manually created groups (so perhaps it's not my code after all!). Presumably, this behaviour is intentional and indicating something.
The nodes still seem to work as expected and produce the same output. What do these dashed links indicate? I haven't spotted the same happening in the Shader or Compositor node editor windows so maybe this is Geometry Node related only.
Note that this was on Blender version 3.00 (I know - it's an unfinished development release... perhaps this is just a new feature...?)