And to tack onto that, it’s part of the broader Operation Condor.
Operation Condor (Spanish: Operación Cóndor, also known as Plan Cóndor; Portuguese: Operação Condor) was a United States-backed campaign of political repression and state terrorism involving intelligence operations, CIA-backed coup d’états, as well as assassinations of left-wing socialist leaders in South America from 1968 to 1989.
Put the map and its key on different sides of the page
Up isn’t North
Bury important information in long paragraphs of descriptive text that are likely to be skimmed at the table. Bonus points if that information is CRUCIAL to set up, pay off, or even resolve a future encounter.
No bullet points!
Sometimes italicized text is meant to be read to the players, sometimes it isn’t. Do not make this clear, so the DM is sure to almost give away an important detail before awkwardly stopping mid-sentence.
Include interesting set pieces, with no rules for how players should interact with them. Is there naval combat? Be sure to provide NO rules, or even guidance, for things like navigating, cannons, boarding, etc.
Or, refer to rules in other books, especially non-core ones so the GM might not have them.
Include custom monsters but omit some stat blocks
Put it all into a PDF with NO bookmarks. Or extremely bad bookmarks. And lock down the PDF to put another hurdle in case the GM wants to fix the bookmarks. (Huge bugbear of mine, honestly, why do so many publishers completely give up on something so easy but so important to the usability of their product?)
The holodecks.