If property portal.space.ordering is used, the portal view should only display the spaces mentioned in the property.
Steps to reproduce:
Create a collection of three or more spaces
copy the help center theme
type in one spaceKey of your collection into the property: portal.space.ordering
visit the portal view
The portal view shows only the one space entered in the property in the given order.
The portal view shows all spaces within the collection, but ordering the two given spaces at the top.