p10 IN/OUT JACK beside sd card socket

HI, I’m from Singapore, Sorry for the poor English.
I just brought a P10 few days ago, and I find 3 In/Out jack beside sd card socket, i read manual but it doesn’t show anything there, i think it is special design for 230v unit?

What does it use for? what does In and Out means?

I think the In and Out are for a 5 volt trigger. When connected to other equipment with similar connectors, turning on one device will turn on the others. I have never used this feature myself but others on the forum likely have.