* As a consequence of previous rules, note the following example :
`lz4 file | consumer` sends compressed data to `consumer` through `stdout`,
hence it does _not_ create `file.lz4`.
+ * Another consequence of those rules is that to run `lz4` under `nohup`,
+ you should provide a destination file: `nohup lz4 file file.lz4`,
+ because `nohup` writes the specified command's output to a file.
Default behaviors can be modified by opt-in commands, detailed below.