I use Emacs org-mode to organise my todo list. Recently I found under each todo item it automatically generates a property drawer containing a key ID and the corresponding value, something like this:
    ** TODO meeting XXX  
       SCHEDULED: <2014-07-12 Sat 14:00>
       :PROPERTIES:
       :ID:       46673B08-F9D9-4966-B70A-A2ADBC2ADE0E
       :END:
       Entered on [2014-07-08 Tue 20:40]
I have no idea how this property drawer is generated, and I did not have it before. If delete it, next time I start Emacs to read the file, it will come back again. What would I do?
 
     
     
    