 While by standard implementation the first matching robots.txt pattern always wins, Google's implementation differs in that Allow patterns with equal or more characters in the directive path win over a matching Disallow pattern.Bing uses either the codice_6 or codice_5 directive, whichever is more specific, based on length, like Google.In order to be compatible to all robots, if one wants to allow single files inside an otherwise disallowed directory, it is necessary to place the Allow directive(s) first, followed by the Disallow, for example