Journal · 18 June 2026
Rent, lamports, and the glossary card on the desk
The rent page is short. The trouble starts when a reader treats lamports as a fee they pay once and then never accounts for them again.
The card is deliberately plain
The glossary card for rent sits in the wooden box on the main desk. One side defines lamports. The other says, in one sentence, that an account needs a balance to stay alive and that the balance depends on how much data it stores. We rewrote it three times because earlier cards tried to be complete and nobody used them.
Readers still argue with the card, which is healthy. The argument we want is about exempt accounts and who paid the lamports, not about a metaphor that hides the balance.
A common slip in path exercises
Week-two exercises ask you to look at two accounts of different data lengths and say which one needs more lamports to remain. People who have only read a tutorial often answer with the fee from a transaction instead. The transaction fee and the rent-exempt balance are neighbours in the notes and strangers in meaning.
When that slip shows up at a checkpoint, we do not add a new shelf. We send the reader back to the card and to one public account in the library folder that is rent-exempt, with the data length written in the margin of their own notes.
Use the card before the circle
The October circle assumes this page is already quiet. If it is not, book a desk hour in September and bring the card with your own example written under the printed sentence. Haru keeps Tuesday afternoons for exactly that page.
Leave the card in the box when you go. The words are short because they have to survive the next reader’s pencil hovering over them, not because the subject is small.