The use of the + and - signs in TCR to show increase or decrease in value codes in TCR is confusing to many collectors. As I mentioned a couple years ago, I really think you should look into using another symbol for this purpose. An "up arrow" or "down arrow" would seem to be ideal.

In this example, T+ is not a T value, plus a little. It means the chip has moved from a lower value to a T in the past year.