Hi Blues: Remember who we're dealing with - hypocrisy is their middle name. To answer about:
"doctrine, or belief, principle, rule"
...you have to go to what they are telling people to do rather explicitly. The latest "new light" really is quite different from past doctrine (pretty old WT to quote from when so much has changed). Dealing with the:
"...or whatever"
...part, sure there are lots of basic ethical standards Christians should uphold - honesty and integrity not being the least, and the specifics of proclaiming yourself to be one of Jehovah's people ("Witnessing about Jehovah") being at the forefront. That was the whole point with Malawi, with WWII...hmm, but not anymore.
That was then, this is now. No one should be lulled into a false sense of security that they will be dealt with honestly or ethically in this new age of "theocratic warfare". Clearly Witnesses now have permission to lie.
Should they answer honestly? Yes. Would a true Christian or witness of God do so? Sure. Is there a specific docttine you can count on today? Doesn't look like it.