<iframethe literal text <iframe (case sensitive) \s+any whitespace character, repeated at least once
.*?any character (except for line terminators), repeated any number of times
\s+any whitespace character, repeated at least once
src=the literal text src= (case sensitive) "the literal " (3410 / 428 / 2216)
.*?any character (except for line terminators), repeated any number of times
"the literal " (3410 / 428 / 2216)
.*?any character (except for line terminators), repeated any number of times
<the literal < (6010 / 748 / 3C16)
\/the literal / (4710 / 578 / 2F16)
iframe>the literal text iframe> (case sensitive)