Sorry for the newb question -- I'm not a modder and only dabble with the notepad elements of modding.

It's been awhile since I've done it, but I inserted this string into the notepad on the map I like to play:
Victory=VICTORY_CONQUEST
Victory=VICTORY_DOMINATION
Victory=VICTORY_CULTURAL

That works fine, but now I wanted to add in diplomatic victory and wasn't sure the proper code. Is it just:

Victory=VICTORY_DIPLOMATIC ?

Also, to save me time in the future, what is the right code for Space Race?

Thanks so much for humoring me

You can find all of them in CIV4VictoryInfo.xml. You are right about the diplomatic victory. Space race is VICTORY_SPACE_RACE.

Thanks for the help! Much appreciated

there is also a hidden victory called VICTORY_RELIGIOUS

edit(to use this you may need to do more than just write it in the mapfile, btw)