1.) “Human Resources” exists for the purpose of limiting the company’s legal liability. Therefore, everything you say or write to them can (and most likely will) be used against you if there is any future employment dispute.
2.) In EVERY organization there are A players, B players, and C players. The A’s are who you want to follow/listen to. The B’s are intimidated by the A’s and will do whatever they can to bring them down to their level, and C’s aren't worth engaging with because they all have 1 foot out of the door but they are CERTAINLY more trustworthy than B's.
3.) The promotion you are most likely to get is the one that you aren’t looking for or talking about to anyone.
What else have I missed?