"Anonymous. I still don't get it. There is only one Backward Walk . The lady or man whoever is going backwards has, according to the book, a TH. It doesn't matter if it is the first step of a Waltz or the first step of a Foxtrot or Quickstep.":
Well, you're wrong, and more importantly you are ignoring the ample evidence that demonstrates why you are wrong.
If there is "only one backwards walk" then you must be reservering the term "backwards walk" for the action literally states in the text. Which is a situtaion without rise or fall of body or foot, without CBM, and perfectly in line with the foot and body without CBMP or side lead. Such an action is essentially never used outside of a class exercise - can you find any example of it in dancing? I can find a few things that come close, but no actual "backwards walks" that meet all of these restrictions.
Or you could use a broader definition of "backwards walk" that includes a great variety of different actions common in dancing, each requiring its own unique adjustments to technique including the detailed foot timing. You have upswing walks and downswing walks, each with their own foot timing. You have side lead walks and CBMP walks, and walks with CBM - again, each with their own details and timing.
Your choice - you can simplify the term to the point where it literally matches the text but does not describe anything usefull in actual dancing, or you can broaden it to include a number of commonly danced actions with their unique details. What you can't do is try to literally and fully apply a specific description to a situation different than the one being described - without coming off as one of those idiots who can recite the text word for word while completeling missing the meaning of what is being said.