What is the {L} Unicode category?

Question

I came across some regular expressions that contain [^\\\\p{L}]. I understand that this is using some form of a Unicode category, but when I checked the documen

Answer 1

Taken from this link: http://www.regular-expressions.info/unicode.html

Check the Unicode Character Properties section.

\p{L} matches a single code point in the category "letter". If your input string is à encoded as U+0061 U+0300, it matches a without the accent. If the input is à encoded as U+00E0, it matches à with the accent. The reason is that both the code points U+0061 (a) and U+00E0 (à) are in the category "letter", while U+0300 is in the category "mark".