title: How to export full or partial content of an org file on demand
body: <p>I wrote some notes on some papers I've read in an Emacs org file so that I can recall what's in those papers by simply walk through my notes. However, for some reasons, I need to print only parts of the notes (I export org file to LaTeX, and it print the pdf file). Of course I can make a replication of that file and delete all the contents I don't need, but I want to know if it is possible to keep writing notes on that file while still being able to print only parts of them in the future. These parts are not continuous. What I imagine is like an <code>#ifndef</code> in C.</p>
  
  <p>Thanks in advance.</p>