Just other event types posted by the same author (or other authors).

Like this:

nevent1qqs298a5ywpqwksf3s7fnywdsffvrrsar6rd3j62sg59qhrku0gxxrsprpmhxue69uhkv6tvw3jhytnwdaehgu3wwa5kuef0qy2hwumn8ghj7un9d3shjtnyv9kh2uewd9hj7w2xrln