initramfs-tools-ubuntu-core has been available since Ubuntu 14.10 (https://launchpad.net/ubuntu/+source/initramfs-tools-ubuntu-core/+publishinghistory?batch=75&memo=75&start=75).
initramfs- tools-ubuntu- core has been available since Ubuntu 14.10 (https:/ /launchpad. net/ubuntu/ +source/ initramfs- tools-ubuntu- core/+publishin ghistory? batch=75& memo=75& start=75).