I'll also add that this seemed foreign when I had patches that had XXX in them I submitted to the linux folks in the early 90s. It was second nature in the BSD side of things. But I don't know if that's a Berkeley thing or a Bell Labs thing Berkeley picked up...

Warner

On Thu, Sep 3, 2020 at 12:11 PM Warner Losh <imp@bsdimp.com> wrote:

The earliest my quick grep could find was 4.0BSD. I didn't find it in this sense in pwb, but it was a quick grep...

xxx is used extensively in prior versions, but there it's meaning is 'placeholder' or 'don't care'. Mostly for /tmp/XXXX files, but also for things like Jxxx handles all the jump commands or dates of the form 24 Feb XXXX or stuff like that.

Warner

On Thu, Sep 3, 2020 at 11:34 AM Dave Horsfall <dave@horsfall.org> wrote:
For yonks I've been seeing "XXX" as a flag to mean "needs more work" or
"look at this carefully, just in case" etc, and I use it myself.

Whence did it come about? I think I saw it as early as PWB, but can't be
sure.

-- Dave, wondering how many nanny-filters he triggered with "XXX"