Files can be uploaded to the wiki and then made available or used on various pages.
Please read Mediawiki's "Managing file" description which talks about how to do this generally on any mediawiki site.
PCSAR's wiki has a few additions described below.
 Confidential files
Files that should not be readable by everyone in the world can be placed in the confidential members-only portion of the wiki.
To do that, prefix the file name with "
Members:" when filling in the
"Destination filename:” of the upload form.
So for instance if the file was a quote from a company that was giving us a great deal on a product, the source filename might be
2016-03-30 acme quote.pdf, you would change the destination filename to
Members:2016-03-30 acme quote.pdf.
Files that begin with
Members: are only accessible to people who are logged in with that access.
PCSAR is using an older version of mediawiki where files that have been upload have their
file description page starting with
Image: instead of
Image: anywhere instructions might say
 Linking to files
PCSAR's wiki has some easier and additional ways to link to files.
Don't scan pages you've printed. There's an easier way.