private function validateTag($tag)
    {
        if (!preg_match('/[.0-9a-z]{3,3}|[.0-9A-Z]{3,3}/', $tag)) {
            throw new InvalidMARCspecException(
                InvalidMARCspecException::FS.
                InvalidMARCspecException::FTAG,
                $tag
            );
        }

        return true;
    }
private function validateTag($tag)
    {
        if (!preg_match('/[.0-9a-z]{3,3}|[.0-9A-Z]{3,3}/', $tag)) {
            throw new InvalidMARCspecException(
                InvalidMARCspecException::FS.
                InvalidMARCspecException::FTAG,
                $tag
            );
        }

        return true;
    }
private function validateTag ( $ tag ) { if ( ! preg_match ( '/[.0-9a-z]{3,3}|[.0-9A-Z]{3,3}/' , $ tag ) ) { throw new InvalidMARCspecException ( InvalidMARCspecException :: FS . InvalidMARCspecException :: FTAG , $ tag ) ; } return true ; }
validate a field tag.

@internal

@param string $tag The MARC spec as string field tag

@throws InvalidMARCspecException

@return true if string is a valid field tag
validate a field tag .