On that link of the documentation:
https://developers.asana.com/docs/attachment
I see that “hosts” can be one of:
asana, dropbox, gdrive and box
And, resource_subtype one of:
asana, dropbox, gdrive, onedrive, box, and external
I suppose I should use “resource_subtype” instead of hosts, but what’s the difference with “onedrive” and “external” to exclude them from hosts?