I don’t think I have ever seen a yellow yield sign in my city. I live in Calgary, Alberta, Canada. We have “free flow lanes” or “weave zones”
Which I guess can be a yield in a way if you need over right away instead of driving in that lane to try and get over you just wait for an opening and then go but its more to say you don’t need to stop/yield as you have your own lane for “x” amount of meters. There’s a few folks that decide to stop or yield instead of continuing to drive and then lane changing.