\ban ASCII word boundary
CUI:the literal text CUI: (case sensitive) \s+any whitespace character, repeated at least once
\S+any non-whitespace character, repeated at least once
\s+any whitespace character, repeated at least once
\S+any non-whitespace character, repeated at least once
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