Trauma journal in therapy?

Has anyone's therapist's ever assigned/asked them to keep a trauma-memory journal? What was its purpose? Was it helpful? How did you use it?

I keep a journal anyway, much of it contains trauma memories because I find writing it down and later sharing it with T helps with the flashbacks. She has not asked em to do a "trauma journal", though she had asked me to write some of the memories down in as much detail as possible, then we go over it in session. Going over it helps me feel not so alone in the memories. Even if we don;t go over all of it thoguh, it helps to write it out and "get it out of me" and onto paper.
It can be really triggering to write it out though. I've found it's easier if I write it spontaneously (without having it assigned) because I'm already triggered, so it doesn't get triggered by thinking about it to write it.

I keep a T journal but it isn't just for trauma memories .I use it more for writing what I would want to say to my t and thoughts about our sessions. I am starting to write in it about some of my experiences but not a lot yet