Simple protocol for approving contents in time series.
We live in the age of paperless. Many good products and solutions for it have already been come up. Sometimes we, however, don't need such sophisticated systems like Certification Authority or Time Stamp Authority to approve some small contents. Just need to prove that the contents is approved before or after other certain contents are done. So I defined this protocol.
I humbly acknowledge that someones did or everyone could come up with this kind of protocol (c.f. Linked Timestamping or Linear Linking protocol). Though, for some interoperability, I decided to open this protocol.