Display of Btech UV-2501 radio The UV-2501 displays +- above the frequency for ALL channels with an offset. Whether it's Plus or Minus.

In the programmer you will set the repeaters appropriately for Plus or Minus with the published offset (generally 600 khz for 2M and 5.0 MHz for 440... but this could be different.) When the file is transferred to the radio, the radio will display the +- for all channels other than those that are Simplex. When you key the mic, the radio will properly shift in the + (Plus) or - (Minus) direction just as you set it up in the program.

This is just how this radio works.