I would think that prowess means a certain skill or talent
SO, I think that a lion who is a great hunter would be described as having prowess
I am not sure but these are an alternative form of writing so that you are able to pronounce the word.
I think the letters are for pronouncing "Anyone"
"Rules and Things Number 63--Never, Ever, say something bad about someone you don't know--especially when you are around a bunch of stranges. You never can tell who might be kin to that person or who might be a lip-flapping big mouthed spy.
The rules showed you how he governed his life and gave you insight into his mind and why he did the things he did and how he survived. I found them fascinating. He had such great life advice, even for adults.