The due tag is just an example of a type of tag you can create with dates as values. The keyword is up to you, can also be say deadline(2 days). A tag can be just the tag (#priority, #important, etc), or can have a value associated with it in brackets following the tag, these values can be:
-
text, e.g.
#priority(high),#priority(low) -
numbers, e.g.
#priority(1),#priority(2) -
dates, e.g.
#priority(today),#priority(2 days)
The advantage of using these values is that you can then search both for all notes with a #priority tag in them, or specifically for notes of say high priority by searching for #priority(high). In the future we aim at extending this functionality such that you could do a search for medium priority and higher for example.
See for more info Tags, People, Emoji's, Text Actions and Links