By complicated and unstated rules, I meant sort of norms about how you talk about previous work, how you caption figures, what order you have for the sections,

By complicated and unstated rules, I meant sort of norms about how you talk about previous work, how you caption figures, what order you have for the sections, how self-congratulatory vs. humble you are, etc. Theoretically, there are no rules for these things. But in practice, insiders seem to adopt a (deliberately?) complex ruleset and use it to signal to each other that they insiders.