> /show.pl?mode=search&input=seat&revy=bil-revyen&index=52
> /show.pl?mode=search&input=seat&index=52&revy=bil-revyen
> /show.pl?mode=search&revy=bil-revyen&input=seat&index=52
> /show.pl?mode=search&revy=bil-revyen&index=52&input=seat
> etc.  Would it be hard to make HTTrack recognize these as
> being equivalent?  Or are there cases where they are not
> equivalent?
It would require some hacking, but this wouldn't be too 
much work. The problem is that, yes, a webserver has the 
right to deliver different content based on parameter order.

Example: a cgi that is calculating the price of a travel 
from paris to new york (airplane), then ny->sf by car, and 
then ->boston by bus, and an open ticket for a car rent 
(this is a pure imaginary travel website)

<http://www.example.com/crazycgi?paris=airplane&newyork=car&sanfrancisco=bus&boston=car>

The page (ans the price!) won't be the same for:

<http://www.example.com/crazycgi?boston=car&newyork=car&paris=airplane&sanfrancisco=bus>

(that is, boston->ny by car, then to paris by car (possibly 
carried by an airplane container (!)), then way back to sf 
by airplane and then a bus rent)

Generally, webserver are "nice" and have no restrictions on 
the argument order, however. But, again, this is not 
mandatory (as least I couldn't find any information in 
<http://www.ietf.org/rfc/rfc2396.txt?number=2396>)