In ABAP/4, we have 2 formatting for comment:

1. Line Comment: If you want to comment whole line, you can put * sign in front of the line.
   Example:
   

   * Comment Line
   WRITE: This is the example for commenting. 

2. Partial Line Comment: If you want to comment partail of line, you can put " sign in front of the comment text
   Example:
   

   WRITE: This is the example for commenting.    "Comment Line