The more easily you can access meaning from symbols without intermediate tools, the more durable and resilient.

Symbols on paper is best.

Plain text in a file that can be opened by any computer comes close, but needs a tool.

Fancy file formats that need not only hardware but also special software are the worst.

However, there's an important tradeoff, which is the fancier formats can present information in ways mere symbols might struggle with, and can also use interactivity to improve understanding.