|Google supports several kinds of extensions to the Standard for Robots Exclusion. Some of them may be life-savers under certain circumstances - making a daunting job trivial in some cases. For example, their support of wildcard filename-matching, in addition to simple (standard) prefix-matching might come in very handy under certain circumstances. |
However, I would never use any of these extensions except in an exclusive User-agent: Googlebot record.
There is simply no telling what any other robot might do with those Google-specific extensions!