I wrote regexps you can steal for these:

```javascript
      // Application Tags are "webmaker.org:foo", which means two                                                                                 
      // strings, joined with a ':', and the first string does not                                                                                
      // contain an '@'                                                                                                                           
      /^[^@]+\:[^:]+/

      // User Tags are "some@something.com:foo", which means two                                                                                  
      // strings, joined with a ':', and the first string contains                                                                                
      // an email address (i.e., an '@').                                                                                                         
      /^[^@]+@[^@]+\:[^:]+/

      // Raw Tags are "foo" or "#fooBar", which means one string                                                                                  
      // which does not include a colon.                                                                                                          
      /^[^:]+$/
```