Well I guess you don't need to draw bearings often being a structural type. That's probably the first thing I used AutoCAD for some 25 years ago, so I know it's not like a new feature
I occasionally do up site plans for some of my projects... thanks for the added info... I was going to see if the method worked on my 2002 version of autocad... glad it's not a new feature...
The @ construction means "relative from the first point selected" You can use distances, angles, etc. So, Line 0,0 @5,5 draws a line approx. 7.07 units long at a 45 degree angle from the point 0,0. It's worth using help to see what other input variations are accepted.