Does "keigo" cover only the use of honorific/humble/polite elements, or does it cover the full range and choice of what to use and not use?


I'm having trouble putting this question into words, especially short enough
to use as the question title, basically I'm confused about what the term
"keigo" applies to:

  * Is it just the addition of honorific, humble, polite, respectful elements to what otherwise might be called a "non keigo" utterance?
  * Or is it a term which covers the whole process or set of rules governing when to apply and not apply such elements?

So is it possible to contrast vanilla plain Japanese to keigo Japanese? Where
is the line drawn? When a single honorific, humble, polite, or respectful
element is added to an utterance does it become a keigo utterance? To make an
utterance totally non keigo do I have to go so far as to remove the o- prefix
from mizu? Is keigo a continuum or an optional extra?

* * *

**EDIT** to clarify the difference between this and [my previous keigo
question](https://japanese.stackexchange.com/questions/882/does-keigo-just-
mean-politeness-or-is-it-a-technical-term-specifically-r):

The previous question was to find out if "keigo" was a
technical/linguistic/grammatical term or just a general term. Now that I know
it's a technical term I'm trying to pin down with this question what it means
and when it should and shouldn't be used.




I think this is a rather hard question to answer, since you'll find people
using the term keigo in both senses. I prefer to use in the first sense, but
it's practically inevitable that keigo training manuals (especially those
directed at foreigners) will also teach about the second one, since knowing
keigo without knowing when and where to apply is kinda pointless.

