There are three fields of meta-data you have to fill in. First of all go to “File > Properties...”.
In the “Description” screen you enter the title of the document. Extension manuals are prefixed “EXT: [extension title]”
In the “User defined” screen you enter your email address as the first field (named “Email” / ”Info 1”)
In the “User defined” screen you enter your full name as the second field (named “Author” / ”Info 2”)
Finally you should also insert the correct extension key in the text below the document title, but this is not a meta-data field, just regular text.