RFC3229 for partial feed retrieval

Bob Wyman, CTO of PubSub, details how RFC3229, “Delta Encoding in HTTP,” could be used to help solve the bandwidth problem of syndicated feeds.

In order to allow the number of entries returned in a feed to be no more than the total number of new or modified inserted into the feed since the last time any specific client retrieved the feed, I propose that we rely on RFC3229 “Delta encoding in HTML” with a new instance-manipulation method defined to provide feed specific delta encoding.