Looks like it doesn't mean anything.
The config parsing code ultimately resolves that text to a number here:
https://github.com/logrotate/logrotate/blob/471f115b18fa8b7dfafecc74f76e34c14d090620/config.c#L1311
stroutll is a standard library function, documented here:
https://linux.die.net/man/
This is OT, but perhaps someone here knows.
In the context of the logrotate conf file, what does the + sign indicate
when used as a prefix size directive?
Example: "size +4096k"
Some conf files have it, some don't. Man pages do not mention it AFAICT
and the internet is rather seems to ignor
