title: What do the different RAISERROR severity levels mean?
body: <p>My best google result was <a href="http://www.xaprb.com/blog/2005/11/23/be-consistent-with-raiserror-severitites/" rel="noreferrer">this</a>:</p>
  
  <ul>
  <li>below 11 are warnings, not errors</li>
  <li>11-16 are available for use</li>
  <li>above 16 are system errors</li>
  <li>there is no behavioral difference among 11-16</li>
  </ul>
  
  <p>But, from BOL, "Severity levels from 0 through 18 can be specified by any user."</p>
  
  <p>In my particular stored procedure, I want the error returned to a .Net client application, so it looks like any severity level between 11-18 would do the trick.  Does anyone have any authoritative information about what each of the levels mean, and how they should be used?</p>