* A misspelling of "you'll": This is the most likely interpretation, as it's a common typo.
* A nickname or shortened name: Some people might use "Yul" as a nickname for someone named "Yuliana", "Yulian", or something similar.
* An acronym: It's possible "Yul" is an acronym used within a specific group or context.
Without more context, it's impossible to say for sure what "yul" means in your specific situation.
If you can provide more information about where you saw "yul" (like the message or conversation it was in), it might be easier to determine its meaning.