.*any Unicode character (except for line terminators), repeated any number of times
PN: the literal text PN: (case sensitive) .+any Unicode character (except for line terminators), repeated at least once
BN:the literal text BN: (case sensitive) \s*a Unicode whitespace character, repeated any number of times
{7}matches exactly 7 characters from the set below:
0-9one character from 0 (4810) to 9 (5710)
.*any Unicode character (except for line terminators), repeated any number of times
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string