DE-MYSTIFYING TECHNICAL ZEROS (Taken from Callerlink 142 October 2000)
Jeff Garbutt

It appears that some callers still don't understand what a technical zero is, and how to tell a true zero from a technical zero. Unfortunately, technical zeros seem to have suffered from bad public relations. As a result, many callers are scared to even adventure down the path of trying to understand them.

So let me put it to you as simply as I can. A technical zero is a module that returns you to the same set-up, but in doing so it exchanges the roles of the heads and sides. If a set-up is created by making the heads active, and a technical zero is used, then the set-up will look as if the sides had been active.

Here is an example:

If we call "Heads square thru 4" - we will have a B1c (or zero box) with the sides on the outside and the heads on the inside. If we do the technical zero - "Split two go around 1 - make a line of 4 - star thru - california twirl" - we will have the same set-up that we would get if the sides did the "square thru 4". (Heads on outside, sides on inside.) The set-up remains the same, the get-out remains the same, but the dancers have exchanged positions.

That's all there is to it. For most callers it is not really necessary to know any more. But for those who do, there is more that can be said about technical zeros:
(1) A technical zero done twice will become a true zero.
(2) A technical zero that works for "same sequence" (boys and girls in the same sequence) set-ups will not work for "different sequence" (Boys and girls have different sequence) set-ups.
(3) A technical zero that works for normal arrangements (BGBG) will also work for half-sashayed arrangements (GBGB) - but will not work for other arrangements, (BBGG, GGBB, BGGB or GBBG).
(4) A technical zero that works for BBGG arrangements will also work for GGBB arrangements but will not work for any other arrangements.
(5) A technical zero that works for BGGB arrangements will also work for GBBG arrangements but will not work for any other arrangements.
(6) A technical zero that is used in a set-up other than it's intended formation/arrangement state will have a "4 ladies chain" affect.

So what use is this to the average caller? Well I believe that an average caller should be able to recognise whether a module is true or technical just by comparing the start and ending set-ups. If the active/inactive roles of dancers are maintained - then it is true. If not - it is technical. So if you use or write lots of modules, it is essential that you understand exactly what the module can or can't do. 

Now to dispel a misconception:

A true zero does not have to return dancers to the same footprints as before. In fact the set can be rotated 90,180 or 270 degrees. I have often heard newer callers make the mistake of saying "8 chain 4 is a technical zero". It is in fact a true zero because it maintains the roles of the heads and sides - even though the square is rotated. I know that this is a difficult concept for newer callers to grasp, but the persons who originally defined the term "true zero" decided not to place a geographical restriction on it.