<athe literal text <a (case sensitive) .*any character (except for line terminators), repeated any number of times
Group 1(\[nggallery[^\]+]*\]) \[the literal [ (9110 / 1338 / 5B16)
nggallerythe literal text nggallery (case sensitive) Negated Character Class[^\]+]* *matches any number of characters outside the set below:
\]the literal ] (9310 / 1358 / 5D16)
+the literal + (4310 / 538 / 2B16)
\]the literal ] (9310 / 1358 / 5D16)
.*?any character (except for line terminators), repeated any number of times
<the literal < (6010 / 748 / 3C16)
\/the literal / (4710 / 578 / 2F16)
a>the literal text a> (case sensitive) g modifier: global. Finds all matches instead of stopping after the first