How do ERRORLEVEL lists work? - Nighthax/AcaciaInstaller GitHub Wiki
In AcaciaInstaller, when it asks you for a choice, it uses ERRORLEVELS to make that possible.
Example:
choice /C 123 /M "Enter your choice:"
:: Note - list ERRORLEVELS in decreasing order
if errorlevel 3 goto :sample3
if errorlevel 2 goto :sample2
if errorlevel 1 goto :sample1
This is a very basic way to ask the user what they would like to do. As you can see here, LIST ERRORLEVELS IN DECREASING ORDER!