Question Language and Terminology?

[Twin Volition]

I'm new to this website and I've been seeing a lot of terminology in use that I'm not familiar with. I'm also concerned about pronouns and what names for things are considered polite/healthy (e.g. how should one refer to one's self as a whole and how to one's "others" or a specific person?). I couldn't find another thread about this in Help Desk, so if I could get some advice on that and some definitions for the following, I would greatly appreciate it:

- dx
- T
- triggering
- grounding
- perp

Thanks in advance.