I am running a family registration form, and in the repeat-loop of ENTER FAMILY MEMBER DETAILS, I need to alert the enumerator that first person should be the head of the household. How do I flash some alert which works only for the first iteration of the loop to show the message (x=1)?
you would use position() to calculate the iteration number within the repeat https://docs.getodk.org/form-operators-functions/#position
And add a relevant criteria to your note when iteration = 1
Kindly create a note field with your message and required = yes
after that set relevance condition if (position=1 and relation!=1). This will help you,