Something I could do without:
The terms "half-brother" and "half-sister."
Let's put it this way: Do adopted siblings constantly refer to one another as "adopted brother" or "adopted sister"? No, they don't; not the ones that I've met, anyway. So if they're allowed to refer to each other as just "brother" or "sister," why are siblings who share one parent not allowed to? I mean, I'm more related to my "half-brothers" than adopted siblings are to each other.
So yeah, I will never use those terms. Ever. To me, they're demeaning and undermine the sibling relationship that I share with my brothers.
Just my thoughts on it, I suppose.