^start of line
Group 1([af][ .]?p[ .]?o|[Pp]*(OST|ost)*) 1st Alternative[af][ .]?p[ .]?o athe literal a (9710 / 1418 / 6116) (case insensitive)
fthe literal f (10210 / 1468 / 6616) (case insensitive)
?matches at most one character from the set below:
the literal (3210 / 408 / 2016)
.the literal . (4610 / 568 / 2E16)
pthe literal p (11210 / 1608 / 7016) (case insensitive)
?matches at most one character from the set below:
the literal (3210 / 408 / 2016)
.the literal . (4610 / 568 / 2E16)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
2nd Alternative[Pp]*(OST|ost)* *matches any number of characters from the set below:
Pthe literal P (8010 / 1208 / 5016) (case insensitive)
pthe literal p (11210 / 1608 / 7016) (case insensitive)
*repeats the group contents below any number of times:
OSTthe literal text OST (case insensitive) ostthe literal text ost (case insensitive) \ban ASCII word boundary
\.*the literal . (4610 / 568 / 2E16) , repeated any number of times
\s*any whitespace character, repeated any number of times
*matches any number of characters from the set below:
Othe literal O (7910 / 1178 / 4F16) (case insensitive)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
0the literal 0 (4810 / 608 / 3016)
*repeats the group contents below any number of times:
fficethe literal text ffice (case insensitive) FFICEthe literal text FFICE (case insensitive) \.*the literal . (4610 / 568 / 2E16) , repeated any number of times
\s*any whitespace character, repeated any number of times
Bthe literal B (6610 / 1028 / 4216) (case insensitive)
bthe literal b (9810 / 1428 / 6216) (case insensitive)
Othe literal O (7910 / 1178 / 4F16) (case insensitive)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
0the literal 0 (4810 / 608 / 3016)
Xthe literal X (8810 / 1308 / 5816) (case insensitive)
xthe literal x (12010 / 1708 / 7816) (case insensitive)
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
i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters