The Resource Credit System Developer Guide is a guide of determining the costs of various transactions on the hive blockchain. The cost of the transaction depends on that transaction type and other various factor that will be gone over later.
The demo that this guide has does not look into the actual blockchain or at transactions, but instead has various example transactions such as vote, short_post, long_post, and transfer. The reference block number and prefix are what they sound like, they are the number of the block the transaction is in, but since these are not actual transactions they are fillers as are all the other values.
With these examples, based on the various values of the aspects of the transactions, like author, permalink size, body size, and tx size, the cost of the transaction is calculated, starting from the code shown in the next picture.
This part of the code looks through each transaction and calculates each ones cost using the function get_transaction_rc_cost. This function calls another function that looks at so many parameters that affect the cost and adds all the costs together. After all the costs are added together, the cost is multiplied by the total hive vesting fund and divided by 1000 times the total vesting share which gives a number associated with each transaction. If you multiply these numbers by 1000, you get how many times you can do each transaction every 5 times.
Overall, working on this has helped me learn a lot about coding and if I wanted to do something with similar to this, I would be more capable than I was before.