Google's web-crawling robots encounter various HTTP signatures while indexing websites. These include 200 OK status codes, which indicate that the request was successful and the requested content is returned; 301 Moved Permanently, which indicates that the requested content has been permanently moved to a new URL; 404 Not Found, which indicates that the requested content could not be found on the server; and 503 Service Unavailable, which indicates that the server is temporarily unable to handle the request due to maintenance or high traffic. Additionally, robots may encounter other HTTP status codes and redirects, as well as various types of security measures such as robots.txt files and meta robots tags.
Google's web-crawling robots, commonly known as Googlebots, may encounter various HTTP signatures, including 200 OK, 404 Not Found, 503 Service Unavailable, and others. These signatures indicate the status of the HTTP response sent by a server to the web crawler. The 200 OK status means that the requested resource was found and is available, while 404 Not Found indicates that the resource could not be found on the server. The 503 Service Unavailable status indicates that the server is temporarily unable to handle the request. Other HTTP signatures that may be encountered by Googlebots include 301 Moved Permanently, 302 Found, and 403 Forbidden, among others.