From the wonderful RedGuides Wiki


This is the {{pipe}} meta-template. It looks like this: | This template should be used if you want to see a vertical bar character as part of the final article.

If you need the pipe character to be parsed with a delay, as in the case of tables or other wiki markup within a template, use {{!}} instead. This template uses the |}} decimal code for the pipe character so that its usage doesn't cause problems when it is used inside a template.