So my friends and I have a permit to hike half dome on July 11th and we planned on doing it in a day but now they're telling me we should do an overnight camp and do the hike in two days. I am extremely confused on how wilderness camping is possible on the way to half dome. So if I am hiking to half dome and want to camp in LYV, I need a permit reservation for the happy isles to LYV trailhead where then no reservation is required to actually camp in LYV, correct? And from what I'm reading on the wilderness regulations (http://www.nps.gov/yose/planyourvisit/wildregs.htm), camping in dispersed wilderness is an option, such as it says I could camp at least at Moraine Dome or two miles from LYV. From reading the Half dome and LYV valley section (http://www.nps.gov/yose/planyourvisit/lyv.htm), it says wilderness permits are needed for the trailheads to lead to LYV. So if I were to camp outside of LYV at Moraine Dome for example, what exactly would I need? If I'm not camping at LYV, I still need a wilderness permit for the trailhead or to simply camp outside of a site?
I'm just really confused on what the wildnerness permit actually is and what it's used for. Because it says it's used for camping in the wilderness, but then it says you need to reserve trailheads. I understand that the Isles to LYV trailhead is already filled up and any permit that I didn't reserve and needed to is probably done already. My question is what exactly is a wilderness permit used for and how could camping on the way to Half Dome be possible now?