With our new upgrades we do now have the option for those who would like to upload and share a pdf file.
How- When you're working in the "message box" to type a post you will find the buttons and options to edit text and so forth. Here you will see a little "paper clip" icon which is for uploading attachments. Once clicked it will pop up a new window "File Upload Manager -Manage all files that you have uploaded" Here you can upload a pdf file and then share it for download in your forum post.
We have just added a new option to embed pdf files into a post that are hosted on a third party site. (Go to this post for more.)
Now we have been working on a more simple option by - (combining both options) - So you can then - upload/share a pdf file here on the forum and embed those uploaded pdf files into your post for easy viewing instead of only having the option for those to download the pdf file.