>   I noticed that when I use WinHTTrack if generates
> a command string for httrack with a -O1 before the
> path instead of -O. This is not documented and I was
> wondering if there is some significance to the
> trailing 1 and if there are other values and there
> meanings.

This is a totally undocumented feature, telling that there is actually only
one argument. You can, with -O, pass either a path for both mirror and cache,
or pass a specific path for each material, using a comma:
  O  path for mirror/logfiles+cache (-O path_mirror[,path_cache_and_logfiles])
(--path <param>)

The O1 option enforce the first form, ignoring any possible comma that may
appear in the option.

ie;

-O c:\foo,c:\bar
will use c:\foo as path to mirror, and c:\bar as path to cache

-O1 c:\One, Two and Three

will use "c:\One, Two and Three" as path for both.