SFO has terminals designated as 1, 2, 3 and international: https://www.flysfo.com/maps/static-maps

Here is how KLM designates the SFO terminal for its flight to Amsterdam:



While it might look like Terminal 1, it actually means Terminal I for International. Bear in mind that nothing official from the airport ever refers to terminal I instead of "International Terminal", nor do any locals refer to the International Terminal as Terminal I.

Putting aside for a second that Terminal I is not used, is there any reason in the world to abbreviate International as I when there is also a Terminal 1 in the same airport?

I assume that over the years people have gone to the wrong terminal because of this.

Air France does the same thing it its app, which is why I a posting here rather than the specific KLM sub-group.