[] matches any character inside the brackets
. matches any character
* matches any number of the last thing
+ matches more than one of the last thing
⁜ matches less than one of the last thing
• matches dead characters
⟦⟧ matches any demons inside the brackets
⸮ matches your hopes & dreams
¡¡¡ matches
ꙮ s̵͞u͡m̶͠m̵͢o͏n̨͡s̵̨͡ ͘͡Z͢͟a͡͏lg͠o̷̷
(?=...) this is called a lookahead assertion. it looks into the future to tell if this regex matches, and returns accordingly.
hope this helps!