The foaf:tipjar property relates an foaf:Agent to a foaf:Document that describes some mechanisms for paying or otherwise rewarding that agent.

The foaf:tipjar property was created following discussions about simple, lightweight mechanisms that could be used to encourage rewards and payment for content exchanged online. An agent's foaf:tipjar page(s) could describe informal ("Send me a postcard!", "here's my book, music and movie wishlist") or formal (machine-readable micropayment information) information about how that agent can be paid or rewarded. The reward is not associated with any particular action or content from the agent concerned. A link to a service such as PayPal is the sort of thing we might expect to find in a tipjar document.

Note that the value of a foaf:tipjar property is just a document (which can include anchors into HTML pages). We expect, but do not currently specify, that this will evolve into a hook for finding more machine-readable information to support payments, rewards. The foaf:OnlineAccount machinery is also relevant, although the information requirements for automating payments are not currently clear.