A Google Webmaster Help thread has one webmaster asking if it is a bad idea to use pipes in the URL. A pipe is this: |. They asked if it is a bad idea to use it in your URL, such as www.seroundtable.com/my|awesome|page.html.
He said when he plugged in a URL with a pipe in it using the Google Keyword Tool, Google return an "invalid website" error response.
Google's JohnMu said he doesn't recommend you use the pipe. He said:
We'll generally crawl and index any accessible and valid URL, I'm sure you'll find many URLs with "pipe" characters in it in our index. That said, just because it's possible doesn't necessarily make it a good idea :-). Similar to using spaces in URLs, those characters may cause issues elsewhere, so personally, I'd try to minimize the risk of problems anywhere by avoiding those kinds of URLs.
Just so you know, an inurl:| search does not return any results:
Forum discussion at Google Webmaster Help.