Devices (computers and phones) manage content from different softwares differently. While yours might incorporate the content seemingly seamlessly someone else may not be able to open it.
Whenever you have content on your site that requires your visitor to have other software installed you should provide a link to an accessible version of the software.
The most prominent example is to to Adobe Acrobat Reader wherever a PDF is present on your website.
- For PDFs provide a link to http://get.adobe.com/reader/
- For Word Documents provide a link to http://office.microsoft.com/en-us/downloads/office-online-file-converters-and-viewers-HA001044981.aspx
- For embed or object tags provide a link to http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash
You may need to install Acrobat Reader to access this document.
The link should include the ending slash (i.e., http://get.adobe.com/reader/ )
As A Courtesy
We recommend that you provide some information about the content, like the type and file size. Some devices will download the content and not all visitors will be happy about downloading a file, especially a large one. The common recommendation for document file size is to keep it below 1 MB.