Hans,
The Quick Base "IF" function is most similar to the Excel "IFS" function.
You can list as many different conditions and results that you want with a final default result for when none of the stated conditions are met. There is no need to embed multiple "IF" functions inside of each other.
Below is how I like to write them out.
Example1
IF ( Condition1,Result1 ,Condition2,Result2 ,Condition3,Result3 ,default Condition )
If one of the conditions is really a combination of multiple conditions then you combine them with "AND", "OR", and parentheses.
Example2
IF ( Condition1,Result1 ,Condition2a AND Condition2b,Result2 ,(Condition3aa AND Condition3ab) OR Condition3b,Result3 ,Default Result )
I hope this helps.