\[the literal [ (9110 / 1338 / 5B16)
urlthe literal text url (case sensitive) Negated Character Class[^]]* *matches any number of characters outside the set below:
]the literal ] (9310 / 1358 / 5D16)
\]the literal ] (9310 / 1358 / 5D16)
Group 1((?:(?!\[\/url\]).)*youtu(?:(?!\[\/url\]).)*) Non-Capturing Group(?:(?!\[\/url\]).)* *repeats the group contents below any number of times:
Negative Lookahead(?!\[\/url\]) \[the literal [ (9110 / 1338 / 5B16)
\/the literal / (4710 / 578 / 2F16)
urlthe literal text url (case sensitive) \]the literal ] (9310 / 1358 / 5D16)
.any character (except for line terminators)
yoututhe literal text youtu (case sensitive) Non-Capturing Group(?:(?!\[\/url\]).)* *repeats the group contents below any number of times:
Negative Lookahead(?!\[\/url\]) \[the literal [ (9110 / 1338 / 5B16)
\/the literal / (4710 / 578 / 2F16)
urlthe literal text url (case sensitive) \]the literal ] (9310 / 1358 / 5D16)
.any character (except for line terminators)
\[the literal [ (9110 / 1338 / 5B16)
\/the literal / (4710 / 578 / 2F16)
urlthe literal text url (case sensitive) \]the literal ] (9310 / 1358 / 5D16)
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