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 documentation, I found only the following "L" categories:

Lu  Uppercase letter    UPPERCASE_LETTER
Ll  Lowercase letter    LOWERCASE_LETTER
Lt  Titlecase letter    TITLECASE_LETTER
Lm  Modifier letter     MODIFIER_LETTER
Lo  Other letter        OTHER_LETTER

What is L in this context?