How to get stream UUID from name

List streams which also contains UUIDs:

I think Tomas meant to say using the -u/--show-uuid option for this purpose, but forgot to put it in the sample command. He knows how to use it apparently according to this post.
https://jazz.net/forum/questions/231330/how-to-get-list-of-components-using-scm-command

So the correct command should be

scm -u y list streams -r "$REPO" --projectarea "$PROJECT" -u "$USER" -P "$PASS"
or
scm --show-uuid y list streams -r "$REPO" --projectarea "$PROJECT" -u "$USER" -P "$PASS"

Reference can be found here in the "UUIDs and aliases" section.
https://www.ibm.com/support/knowledgecenter/en/SSYMRC_6.0.2/com.ibm.team.scm.doc/topics/c_scm_cli.html