Linking to PDF file (and others)?

When one uploads an image file, it presumably resides somewhere on the HO servers (or on some portion of the server that HO rents from an internet service provider), and can be summoned from there to appear embedded in a post. That’s as it should be. A picture is worth, I’m told, many words, and ought in most cases to be in the post.

But what if one wants to provide a link to something, an image irrelevant to the main point of the post, but of tangential interest, or, more importantly, a pdf file? Is there a way to upload it to HO, link to it in a post, but not have it appear in the post?

My main interest is in providing links to documents (recipes, for instance) that I’ve carefully formatted and have available in pdf format, but that would not show up clearly as images in a document. I know I can upload them to an external server, then provide a link to that, but is there an in-HO-house solution?

Uploading was defaulted to common picture formats only previously. It now includes PDF and common audio, video formats. If you can think of relevant formats, just comment. I think the primary concern is viruses in formats beyond media.