How about a categorizing the documents in the inbox view like this:
>Urgent
>Calendar Events
>Normal
Here is the column code I'd suggest:
First a hidden sorted column:
@If(
Form="Notice":"Appointment" & Importance != "1"; "2.Calendar Events";<br/>
Importance="1"; "1.Urgent"; <br/>
"3.Normal"<br/>
);
Then a visible categorized column:
@If(
Form="Notice":"Appointment" & Importance != "1";"Calendar Events";<br/>
Importance = "1"; "Urgent";<br/>
"Normal"<br/>
);