WhatsApp is sending out a new feature that lets you send files directly through the popular messaging service.
Some have spotted a server-side switch that enables you to share PDFs (the only supported file type for now) to another contact.

When you touch the paperclip button you’ll see an option to send a document, along with buttons for Camera, Gallery, Audio, Location, and Contact.
However, if the recipient doesn’t have the update, you won’t be able to send anything

Wow that's great news!! I use it with Telegram a lot!