What are the messages?

Question

phpstorm

$pattern = '#<script.*?>.*?</script>#si';
highlights #si at the end, where it outputs:
# - top level '#' expression
si - Unresolved variable
Does something need to be corrected and how, if necessary?

Answer 1

I think the storm incorrectly determines the contents of the string and tries to "see" the JS there.
If the error confuses, you can try to replace the limiters in the regular expression: At least it helped me.