What's the difference between postgresql.conf.sample and postgresql.conf.sample.orig

I see the above-mentioned files in src/backend/utils/misc.  A diff shows
the following:

$ diff postgresql.conf.sample.orig postgresql.conf.sample
223a224
> log_destination = 'syslog'
302a304
> silent_mode = on
363a366,367
> 
> autovacuum = on

What's the purpose of postgresql.conf.sample.orig?

I'm adding a GUC variable to submit a patch to allow tracing temp file
usage.  Do I need to add it to both?

-- 
Bill Moran
Collaborative Fusion Inc.