The * metacharacter in BRE 1s, ERE 1s and PCRE 1s matches 0 or more occurences of the previously grouped pattern (if a grouped pattern is preceding the * metacharacter), 0 or more occurences of the previous character class (if a character class is preceding the * metacharacter) or 0 or more occurences of the previous character (if neither a grouped pattern nor a character class is preceding the * metacharacter)
