.htaccess with or without slash

What do I need to do to the following rewrite rule to make it so it works whether or not their is a slash at the end of the URL?

ie. http://mydomain.com/content/featured or http://mydomain.com/content/featured/

RewriteRule ^content/featured/ /content/today.html

From stackoverflow

• Use the $ to mark the end of the string and the ? to mark the preceding expression to be repeated zero or one times:

  RewriteRule ^content/featured/?$ content/today.html
  

  But I recommend you to stick to one notation and correct misspelled:

  # remove trailing slashes
  RewriteRule (.*)/$ $1 [L,R=301]
  
  # add trailing slashes
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteRule .*[^/]$ $0/ [L,R=301]
  

  Unkwntech : +1 mostly for the additional info, although I was gonna' give it to you anyway.