The AGG TEC™ reference number located between mile markers above the elevation profile is the measure of Total Elevation Change per segment. These are also commonly referred to is PUDs or MUDs (Pointless Ups & Downs or Mindless Ups & Downs). This rating is meant to give you an idea of how TEChnical the terrain ahead of you will be.
For instance: If, during the course of a 3 mile segment, you climb 1000 feet and descend 500 feet, the AGG TEC™ number for that 3 mile segment would be 1500. This number, when compared to the elevation profile, can give you an idea of how much elevation change is ahead and whether it is likely to be more uphill or downhill or a mixture of both ups and downs.
At the top, in the blue bar on the elevation side of each profile, is an AGG TEC™ reference number for the entire section of the trail that the map covers.
This is what the TEC™ numbers look like. They are the grey numbers in between mile markers: