I have a config I need to translate to another firewall. I believe the following means that (where a.b.c.d is an external ip)
ip nat inside source static tcp 192.168.1.145 443 a.b.c.d 443 extendable
From the outside world 443 access is allowed to 192.168.1.145 via the translated outside address of a.b.c.d
Your understanding is correct. The static statement means that anybody on
the outside world try to connect to a.b.c.d on port 443, it will be
translated to 192.168.1.145 port 443. You need to have appropriate
access-list entry to allow the traffic as well.