(?i)applies the following effective flags to the remainder of the pattern: gmi i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters
\ban ASCII word boundary
*matches any number of characters from the set below:
pthe literal p (11210 / 1608 / 7016) (case insensitive)
*repeats the group contents below any number of times:
ostthe literal text ost (case insensitive) \.*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 (11110 / 1578 / 6F16) (case insensitive)
*repeats the group contents below any number of times:
fficethe literal text ffice (case insensitive) \.*the literal . (4610 / 568 / 2E16) , repeated any number of times
Positive Lookbehind(?<=po|p.o|o\.|office|post) pothe literal text po (case insensitive) pthe literal p (11210 / 1608 / 7016) (case insensitive)
.any character (except for line terminators)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
\.the literal . (4610 / 568 / 2E16)
officethe literal text office (case insensitive) postthe literal text post (case insensitive) \s*any whitespace character, repeated any number of times
bthe literal b (9810 / 1428 / 6216) (case insensitive)
othe literal o (11110 / 1578 / 6F16) (case insensitive)
xthe literal x (12010 / 1708 / 7816) (case insensitive)
\ban ASCII word boundary