Multiple Measurement description allows you to select multiple measurements at one time by use of the Multi-Select Tool and then changing the description of those selected measurements all at one time by clicking the "D" key on your keyboard.
Press the Letter "D" on your keyboard after you make your selections on your drawing and the below entry popup box will appear allowing you to label your measurements.
Click on the link below to view a video on Multiple Measurement Description.
Click on the link below for Online Help Documentation.
Multi Select Tool Documentation
Description Edit Window Documentation