Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
Literally:
Match a non-# character
[^#]
followed this whole pattern recursively
(?R)*
repeated any number of timesfollowed by 1 or more # characters
#+
OR 1 or more # characters at the start of the string
\A#+
FYI, regex101.com is a great tool for explaining regex.
i forgive you