Why does "file" change the creation time on some Unix systems?

[Chris Hill]

In article <> guy at auspex.auspex.com (Guy Harris) writes:
>If what you say is completely true, you must be running a pretty bizarre
>version of UNIX; no version I know of maintains the *creation* time of a
>file. 

If so, to what "creation" time does the -c option of ls refer?

Chris Hill
chris at nyquist.bellcore.com