Pattern[/(?x) ^ (? (? (?: [[:alpha:]] [[:alnum:]_-]* | (?: (?: oid | OID ) \. )? [[:digit:]]+ (?: \. [[:digit:]]+ )* ) [[:space:]]* = [[:space:]]* (?: \# (?: [[:xdigit:]]{2} )+ | (?: [^,=\+<>#;\\"] | \\ [,=\+<>#;\\"] | \\ [[:xdigit:]]{2} )* | " (?: [^\\"] | \\ [,=\+<>#;\\"] | \\ [[:xdigit:]]{2} )* " ) ) (?: [[:space:]]* \+ [[:space:]]* \g )* ) (?: [[:space:]]* [,;] [[:space:]]* \g )* $/]