Why isn't SupportsNoItemContext supported in office 365 add-ins?

Ryan Milner 1

The SupportsNoItemContext property for the ShowTaskpane Action isn't in the online specification (linked below) but works fine on the local outlook client. In fact I can't find a reference to it anywhere on the internet and only found it looking at the Insights plugin installed in my Outlook.

Because its not in the online specification I cannot upload it to our office 365 admin to push out to users.

I'm trying to allow a task pane to be opened when no item is selected and this is the only way I can find that allows it.

https://learn.microsoft.com/en-us/openspecs/office_file_formats/ms-owemxml/8e722c85-eb78-438c-94a4-edac7e9c533a

Example:

<Action xsi:type="ShowTaskpane">  
    <SourceLocation resid="DFA16BE7917A23C52030E8311AF8C22F" />  
    <SupportsPinning>true</SupportsPinning>  
    <SupportsNoItemContext>true</SupportsNoItemContext>  
</Action>