\ba Unicode word boundary
patthe literal text pat (case sensitive) \d+a Unicode decimal digit, repeated at least once
=the literal = (6110 / 758 / 3D16)
.*?any Unicode character (except for line terminators), repeated any number of times
Positive Lookahead(?=\s*\bpat\d+=|$) 1st Alternative\s*\bpat\d+= \s*a Unicode whitespace character, repeated any number of times
\ba Unicode word boundary
patthe literal text pat (case sensitive) \d+a Unicode decimal digit, repeated at least once
=the literal = (6110 / 758 / 3D16)
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