Ground black or white pepper
With care — Allowed by some hospitals and not others, or allowed only prepared a particular way.
In one line: Use a small pinch, finely ground, or leave it out.
Pepper is an unusual case. The leaflet this book follows lists herbs and spices under foods to avoid, and in the same document lists pepper among the things you may have. Both statements are on the page.
The most likely reading is a practical one. Finely ground pepper at the quantity a household actually uses is a dust rather than a set of pieces, and it dissolves into a sauce. Whole peppercorns, cracked pepper and a coarse grind are a different matter and are not what this book means.
The preparation
A small pinch of finely ground white pepper, or leave it out. White rather than black, because it is milder and disappears into a pale sauce. Ground fine, not cracked. Added at the end so that a pinch is a pinch and not an accumulation.
Every recipe that offers pepper marks it optional and says it can be left out without changing anything else.
Where hospitals differ
St George's allows dried spices, which covers ground pepper comfortably. Leeds allows dried spices at stage three of its obstruction diet. The leaflet this book follows is the ambiguous one, and this book resolves the ambiguity in the reader's favour while flagging it every time.
If you have been told to leave it out
Nothing here depends on it. Salt, a good clear stock and cheese do the work. Carbonara without pepper is a quieter dish and still a proper one. See herbs and spices.