Name ▲ ▼	Value ▲ ▼	Description ▲ ▼
Default		Default grammar; ECMAScript is the default
ECMAScript		JavaScript-like regex grammar
basic		Basic POSIX grammar (BRE)
extended		Extended POSIX grammar (ERE)
awk		awk POSIX grammar
grep		grep POSIX grammar
egrep		egrep POSIX grammar
ICU		+++ International Components for Unicode will be the new default