Through this thread, I just noticed that it is possible to set the default terminology entry through application settings. But when I go there and choose my terminology, select button grays out (and it stay grayed out for every other entry in the dropdown, including slicer’s defaults segmentation terminology).
This is in 5.6.1
Found that it grays out whenever an item in the left list has been unselected; and remains gray even if all the items are selected again.
If you choose a property then the “Select” button becomes enabled and you can click on it to accept the selection.
Yes indeed, it was too obvious 
I might have misunderstood what this selection achieves. I want to make the custom terminology i installed as the default terminology to be used. I thought thats what the selection achieves.
I dont need to select a term.
That’s exactly what this does.
You have to select a complete term, because this will be used in the Segment Editor by default for new segments if you don’t select anything else.
I’ve tested this and it works well.
Color for segments with default terminology is automatically generated (to avoid using the same color for all segments). Maybe this was what you did not expect?
If a module registers the terminology dynamically then the terminology entry is not available at startup and you will get a warning message. Maybe you find this message misleading? The setting is still used, so you can ignore the warning. To fix it, you can make your module copy the terminology file to the application settings folder or you add the file manually using the “add file” buttons in the terminology selector:
User-defined terminology files are stored in the Terminologies subfolder in the application settings folder. On Windows, it is something like this: c:\Users\YourUserName\AppData\Roaming\slicer.org\Terminologies. You can get this folder name by calling slicer.modules.terminologies.logic().GetUserContextsPath().
Thank you for the reply!
