I've seen two undefined text strings. I haven't had time to upgrade and am still playing v095, so sorry if these were already fixed.
a) I got a mission about the Council being upset about me sharing tech with certain organizations. I didn't get there in time, and the box that popped up said "STR_XCOM_SLANDER tracking lost"
b) Using Hyperwave Decoder, I saw a UFO description for "Very small Cthonite Light Fighter." The last line said "Zone: REGION_HELLO_WORLD"
I also have a suggestion. Several months of in-game time passed between me researching Syndicate HQ and getting the actual mission. This was many, many hours of playing time, and when the equip soldiers screen came up I was initially confused because I'd long forgotten about
"She's a MAN, baby!" --Austin PowersKind of a funny story, the thing that really caught my eye was that when equipping the troops for that mission, I suddenly found out a hybrid of mine who'd been on over 20 missions was a girl when I finally saw her without armor. I had no idea, I thought she was a dude the whole time. From now on, I'll take a closer look at those hybrids before I equip them in armor for the first time.