Rate limiting is a defined amount of use that a user or application can gain from an API or service. For instance, our local search API has a rate limit of 5,000 queries per IP per day and to non-commercial use. In many cases, when that limit is hit, the API or service will cease to send back search data (or whatever service you may be using).
That sentence (if I'm understanding the context correctly) basically means that if you're using an API outside of YQL and are making hits against the general access URL you will be affected by the normal rate limits of the API. If you are accessing these API's through YQL with a signed OAuth request (e.g. from within the PHP SDK using the query method or using the OpenSocial gadgets.io.makeRequest JavaScript request) then you are not affected by those standard rate limits.
Hope that helps.
Jonathan LeBlanc
Senior Software Engineer
Yahoo! Developer Network
Could you describe more clearly what is rate limiting please?
"The public URL has stricter rate limiting, so if you plan to use YQL heavily, we recommend you access the OAuth-protected URL."
