-dit(bf(-p, --perms)) This option causes rsync to update the remote
-permissions to be the same as the local permissions.
+dit(bf(-p, --perms)) This option causes rsync to set the destination
+permissions to be the same as the source permissions.
+
+Without this option, each new file gets its permissions set based on the
+source file's permissions and the umask at the receiving end, while all
+other files (including updated files) retain their existing permissions
+(which is the same behavior as other file-copy utilities, such as cp).