Mostly a "what if" scenario, but it's always bothered me that VTI is the US-total market and VT is the international/world total market. Everything in me wants to read it as "**V**anguard **T**otal Market" and "**V**anguard **T**otal Market **I**nternational".
Likewise, I wish Vanguard's Emerging Market (VWO) was VEM and Developing Markets (VEA) was VDM because I regularly confused them.
Are there other symbols that seem "wrong" to you? Or have any of them ever swapped to make it less confusing?