By default, whatever post in my journal that you, being a person and hopefully not a robot $nigerian/$russian/$political/$religious
And if you don't have a name that LJ can recognize, you won't be allowed to post, at least if the software is working correctly.
I will moderate most posts automatically; it's my default now. I will delete as spam or as abusive anything that becomes threatening, or is an attempt to swindle me, or is just someone passing on the latest internet meme where it doesn't belong.
If you post pseudonymously and spam or troll and don't leave a name or obvious identification so I know you're real, I will at least delete, and may report as spam or abuse, and this mean that the administrators of Livejournal will in their own time get around to doing something themselves, perhaps blocking your access.