The wording in their manual is certainly an odd word salad and I can only speculate as to why SSI decided to write it this way.The old English teacher in me struggles to understand that.
Since there is no enforcement of the this, the word required cannot mean anything akin to the phrase "required by law." It is more likely a synonym for needed, as in "A standard bechamel sauce requires the blending of equal parts flour and melted butter." They further diminish the impact of the word required by labeling it as a recommendation. Finally, they diminish it further by saying that if you follow the required recommendation, you can be reasonably assured....
So, I need to ask. You said, "Not to pick a fight over this, but the SSI recommendation of 24 hrs is also a minimum standard." How can a recommendation be a standard?
I used the word "standard," because that is the language the writer of the post I responded to used in their post about "minimum standards." My purpose was to point out that, he too, was meeting only "minimum standards," by following SSI guidelines/language/recommendations and not exceeding them as he claimed.
On a similar note, you stated that you are an "old English teacher." Are you currently an English teacher who is old, or do you mean that you used to be an English teacher? For example, I had an acquaintance who stated they were a "former large animal doctor." Does that mean they used to be a doctor for large animals, or were they currently a doctor for animals that used to be large?