You can add bookmarks to the Sorter by pressing the Command-Option modifier keys while dropping the link. Stuff dropped to an inbox should be also marked as unread. However, we’ll unify this in a future release.
Dragging a URL onto an Inbox in the Sorter creates a webarchive. This is counterintuitive – especially considering that when I drag a URL directly into DT (2.0.6) it creates a bookmark.
Regarding the Sorter, the documentation states: “For URLs dragged from a browser this creates a bookmark and does not add a web archive of the page.”
Dragging a URL into DT with or without keyboard modifiers (command; command-option) just creates a bookmark.
I believe the text that precedes what you cited from the manual fully describes the behavior:
“Command-Option-drag to add only a reference of the item to DEVONthink Pro Office
(index). For URLs dragged from a browser this creates a bookmark and does not add
a web archive of the page.”
Command-option-dragging to the Sorter creates an indexed document, unless the item being dragged is a URL. The documentation is accurate, even it one considers the behavior inconsistent. However, there is a bug in this behavior-documents (not URLs) that are command-option-dragged to the Global Inbox will still be imported. Documents dragged to other inboxes in the Sorter will be correctly indexed.