title: Regex to match Australian Business Number (ABN)
body: <p>I need a regex to match a value in which each character can be a digit from 0 to 9 or a space. The value must contain exactly 11 digits.</p>
  
  <p>For example, it should match values in the format '012 345 678 90' or '01234567890'.</p>
  
  <p>Can anyone please help me on this?</p>