How can an SQL Server instance be removed via the command line without removing the whole database engine?

I am passing the following parameters:

/QS /IACCEPTSQLSERVERLICENSETERMS="1" "/ENU="True" /INSTANCENAME="MYINSTANCENAME" /FEATURES="SQLEngine" /ACTION="unInstall" /INDICATEPROGRESS="True"

This causes the whole database engine and all instances of the SQL Server version to be removed.

Is it the/FEATURES parameter that needs to be changed?