Originally Posted by Quorcork
Whoops, i just found that OF does not link but copy PDFs into the actions.
By default, OmniFocus does
link files dragged to the notes field of an action. Nothing gets embedded except a pointer to the actual file location. You can verify this by right-clicking on the attached file and choosing "Reveal in Finder". Then check the file's path by right-clicking on the proxy icon in the title bar of the file's window or go to View -> Show Path Bar in the Finder.
Linking files will keep your database smaller and changes to the original are immediately available from your database since the database is just linking to the original. However, linked files are not
available on a synced iPhone or on another Mac.
You can also embed files into the OmniFocus notes field by holding the Option key when you drag a file in, or by going to Edit -> Attach File... in the OmniFocus and selecting "Embed the file in the document" from the file selection sheet.
Embedded files will make your database larger. But the big advantage is that they will also be available on synced Macs and iPhones (assuming it's a file type the iPhone can display, like PDF).
One caveat with embedded files: editing the embedded file currently doesn't save the changes back to the database (i.e. the changes are made to a temp file that doesn't get re-embedded). So even though it looks like you might be able to modify an embedded attachment, it's really a read-only solution for now.
All things considered, I vastly prefer linking in all my attachments. If there's some bit of reference material I need on my iPhone, I either email it to myself or send it to my iPhone with FileMagnet