The current output of -Xlog:help is as follows:

```
 -Xlog:gc::uptime,tid
Log messages tagged with 'gc' tag up to 'info' level to output 'stdout', using 'uptime' and 'tid' decorations.

 -Xlog:gc*=info,safepoint*=off
Log messages tagged with at least 'gc' up to 'info' level, but turn off logging of messages tagged with 'safepoint'.
(Messages tagged with both 'gc' and 'safepoint' will not be logged.)

 -Xlog:disable -Xlog:safepoint=trace:safepointtrace.txt
Turn off all logging, including warnings and errors,
and then enable messages tagged with 'safepoint' up to 'trace' level to file 'safepointtrace.txt'.
 -Xlog:async -Xlog:gc=debug:file=gc.log -Xlog:safepoint=trace
Write logs asynchronously. Enable messages tagged with 'safepoint' up to 'trace' level to stdout
and messages tagged with 'gc' up to 'debug' level to file 'gc.log'.

```

It seems that a newline is missing before the last example.