Same thought. The one on the left just conveys "notes" to me. Middle actually seems to be about a more "well put together" document. A fountain pen by itself do

Same thought. The one on the left just conveys "notes" to me. Middle actually seems to be about a more "well put together" document. A fountain pen by itself doesn't necessarily mean documents to me, but signing them. As you, never seen these icons in my entire life.