If there's an official traffic sign indicating that you should park head-in, then you should park head-in.
So, your citation would indicate there was some sort of sign that you took to only apply to others.
If you want to "fight it", you can contest the ticket. Based on what you have posted, we can assume that you did not park head-in. Therefore, the question is, was the signage present? Not noticing the sign doesn't count. But if there was no signage at all, then that is what you could try to argue.
Or you could try getting the ordinance amended. Which would take longer and cost more than your ticket - and can't be applied retroactively, so you'd still have to pay the ticket anyhow. But hey, everyone needs a hobby.