The main Jam limit is 1024 characters of code (e.g. using the character counter in PICO-8) - as it's simple to adhere to. However, for people used to working on byte size limitations, then there is an (optional) limit you can follow, which is 1024 bytes of compressed code (e.g. using the upcoming compressed size counter coming in PICO-8 v0.2.4d)
That does also mean that if you follow the compressed byte limit, that you can theoretically have more "code" than if you went with char count (depending on how well your code compressed). But, I guess the trade-off is slightly more complex export/loading process.
Going forward - once the "compressed/byte count" becomes an established feature of PICO-8, I may simplify this Jam and have just the compressed count. However, this is still VERY new to PICO-8 (+the Jam's origins were born out of char count jams like TweetJam + TweetTweetJam). So, I guess we'll see!
Hope that answers your question - but if not, feel free to hit me up for more details. 馃
