title: tilde, dlm and colon format modifier in list input
body: <p>There are 3 concepts i would like to clarify. <code>:(colon format modifier)</code>, <code>~(tilde)</code> and <code>dlm=</code></p>
  
  <pre><code>data scores;
      infile datalines dsd;
      input name : $10. score1-score3 team ~ $25. div $;
      datalines;
  Smith,12,22,46,"Green Hornets, Atlanta",AAA
  FriedmanLi,23,19,25,"High Volts, Portland",AAA
  Jones,09,17,54,"Vulcans, Las Vegas",AA
  ;
  run;
  </code></pre>
  
  <p>Firstly, usage of <code>:</code> in input statement can totally replace <code>length</code> statement? And why i do not need <code>:</code> for team variable sth like <code>team : ~ $25.</code> ?</p>
  
  <p>Secondly, why sas can automatically recoginize <code>,</code> is the delimiter but not <code>"</code> or <code>blank</code> ?</p>