pecial character class in Regular Expression code example

Example 1: grel general expression character classes

. any character (almost*) 
\ escape character
| or
\A or ^ anchor: start of string
\Z or $ anchor: end of string
[] list or range to be matched
[^] negative list or range (NOT these characters)

Example 2: grel general expression character classes

\p{L} - letter
\p{P} - punctuation
\p{InBasicLatin} - in basic Latin Unicode block
\p{InArabic} - in Arabic Unicode block