Hey @Marie and @Emily_Roman,
I think I found an issue in the docs. Please see:
The text says
The parent task should be located above the current row in the CSV file.
(emphasis mine)
But the accompanying screenshot shows the exact opposite: it shows the parent task below its subtask.
@Phil_Seeman you are a magician with this stuff. I should have you proofread my emails. Might be a full time job though 
@Phil_Seeman, thank you so much for the report! 
I’ve gone ahead and filed a task for our Guide team to fix this, I’ll keep you posted as soon as I have an update!
I can’t help it, I was born with this affliction. (My kids consistently forced me to proofread their college papers, up through my daughter’s medical-school-application essays this year.)
Hi @Phil_Seeman 
Just a quick note to let you know that our team fixed this issue in the guide. the fix should be live in the next day or two! Thanks again for reporting this issue!