Me.Position.X Source?

[fuly]

Where do this tags come from? Is there source code on svn for them?
- ActorExistsAt(111907, Me.Position.X, Me.Position.Y, Me.Position.Z, 50)
- <While condition="Me.IsInBossEncounter">
- Me.Position.X

I havent found a documentation about this tags in forum or in questtools
https://subversion.assembla.com/svn/questtools/trunk/QuestTools/ProfileTags/