title: Difference between %CHECK() and %checkr() in RPGLE?
body: <p>I visited many sites but could not get any satisfactory answer. Please, help me to understand this one. I tried to make a program but could not understand. 
  I tried:</p>
  
  <pre><code> String  = 'AABC1ABD2AB3A';                         
  
   Pos = %check ('ABCD' : %trim(String));             
   dsply pos;   
  </code></pre>