/etc/cloud/cloud.cfg.d/README is in cloud-init 18.2-14-g6d48d265-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # All files in this directory will be read by cloud-init
# They are read in lexical order. Later files overwrite values in
# earlier files.
|