Eclipse plugin uses deprecated hash symbol # for comments in newly created .drl
files. Setting # to be deprecated might cause large refactoring work in
existing .drl files, because Eclipse plugin used this type of comment as a
default setting. Newly created .drl file in Eclipse looks like this:

#created on: Feb 22, 2012
package com.sample
#list any import classes here.
#declare any global variables here
rule "Your First Rule"
when
#conditions
then
#actions
end

Users should now use // for single comments and /* */ for block comments. But
Eclipse plugin should not confuse them with #.