GUID, Owner GUID, Legacy GUID... What's the difference?

[Mikeeeyy]

I noticed a player joining my server before with all the following info:

Player #24 Hater (ip:port) connected
Player #24 Hater - GUID: efd3477947a76ae750a21805356b89e1 (unverified)
Verified GUID (efd3477947a76ae750a21805356b89e1) of player #24 Hater
Player #24 Hater - Owner GUID: a0f8b4bf3522f6a38c13a76c3f07acd2
Player #24 Hater - Legacy GUID: e633f396495a3d763a6a9f9aa58cc584

In my rcon it says this player is using this GUID: a0f8b4bf3522f6a38c13a76c3f07acd2, which is the Owner GUID.

This is the info for another player:

Player #20 Blood Fang (ip:port) connected
Player #20 Blood Fang - GUID: 0d6f372d72c7d402beb32574b89ddf46 (unverified)
Verified GUID (0d6f372d72c7d402beb32574b89ddf46) of player #20 Blood Fang
Player #20 Blood Fang - Legacy GUID: d70a03a1488c78c13d921d8548a6ffa3

This one only has GUID and Legacy GUID and my rcon says he is using: 0d6f372d72c7d402beb32574b89ddf46, which is his GUID.

My question is what's the difference between these 3 GUIDs? If they have an Owner GUID does this mean they're using Steam family share?

If somebody could please explain in depth the difference between these GUIDs I'd be most grateful, thanks.

Edited August 25, 2015 by Mikeeeyy

[Richie]

Legacy is from the old Gamespy activation, my original A2 and OA were on disc, once Gamespy closed i had to redeem my key through Steam, this then gave me a new GUID, so that's 2 accounted for, the 3rd i've no idea, might well be a family sharing reference.