Google's John Mueller answered a question on Twitter asking if it is okay to use a decimal point in your URLs, such as mysite.com/page.goes.here/. John Mueller said you surely can but he said it was a "bad idea."
Here are the set of tweets:
John then added that he has even seen domains with decimal points in them:
Google's John Mueller said in general, using special characters should be avoided in your URLs.
Forum discussion at Twitter.