It's not important, but I wish there were a way to control the line numbers when posting code. As it is, I've never seen code that doesn't start at line 1 and count up from there, but that's not always ideal. Sometimes there is boilerplate at the top of a file that people don't need to see, and sometimes someone wants to suggest a modification to something someone else has posted. Either way it would be helpful if the line numbers could be made to match the original code even though only a part of it is being posted. It would at least be more elegant that way.
Often compiler error messages will include line numbers and that forces people to either post entire source code files to make the line numbers match, or else put the real line numbers in comments, or edit the error message to make the line number in the message match the line number in the post.
I have no idea how difficult this feature would be to add, but perhaps instead of a blank line before some code there could optionally be a notation that would change the number of the first line.