Thomas Graf wrote:

* Herbert Xu [ref] 2005-04-28 13:20

quoted

iptables -D INPUT 2

Except for when another iptables instance has modified the ordering of
the rules by inserting or deleting a rule in the meantime. Please do
not adopt this scheme, it's completely unreliable.

Yes, if you don't know the ordering of your ruleset it is unreliable :)

Regards
Patrick