Question on VAF4A-please help

[Karra]

I am drafting my application to submit in February. I have a few questions and would appreciate your advice.

In travel history 6.6 '' Have you ever voluntarily elected to depart the UK...'' If I am an over stayer, I need to tick yes, right? And what shall I put in the box for date, reason, reference number? Are they asking for the visa details on which I was in the UK before overstaying?

Same for 6.4 Have you been granted any UK visa? What is the purpose-visa type? I am quite confused. Please help!!!

Many thanks