Why do some posts require approval, while others seem to go up instantaneously?

Since someone bumping the thread I made requesting an edit button attracted mod attention, I thought I would try reviving this thread.

I am becoming increasingly frustrated with virtuality all my posts being held for approval, and some never approved at all, despite not breaking any rule I am aware of. Has my account been blacklisted? Is there some word I am using that triggers an automated filtering system?

It cannot just be the length of posts, because I have had long posts appear without waiting for approval and posts only a couple of sentences long be held.

Please, moderation team. I would like some insight. I am sure you do not like having my posts constantly added to your approval backlog either.

What can I do to avoid the vast majority of my posts being held for approval?