You can name your ships, planets, and ship classes whatever you like in Space Empires IV (SE4), and I've never seen a profane name. The worst names I saw were my own, when I was roleplaying the EEEvil Oooze, and even those didn't get very bad.
SE4 players _do_ use deceptive or changing names sometimes to deceive enemies, though there it's generally considered a neat feature. Renaming ships is a bit different than renaming people. On the other hand, it was fairly common historical practice to deploy decoys dressed as kings and princes to protect the real ones.
I didn't know I could rename characters in Dom I, and slightly enjoyed having to live with the names, except when they repeated. Repeats made some things kind of confusing, like the Hall of Heroes list.
Now that I know I can, I may rename or add epithets to some of my men.
It'd be interesting to be able to tag enemy units, as "licker" and Psitticine suggested.
I suppose the ability to rename could be an option which the person who creates the game can set ON or OFF.
PvK