Why is \p{Lu} matching lowercase letters?

Question

Lu is supposed to represent Letter, Uppercase, however I am getting unexpected results

PS > 'Hello World' -replace '\p{Lu}', 'Z'
ZZZZZ ZZZZZ

As can be seen, Lu is replacing upper and lower characters.

§ Regular Expression Category

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Answer 1

Use -creplace. -replace is case-insensitive:

PS > 'Hello World' -creplace '\p{Lu}', 'Z'
Zello Zorld