This is essential when you're doing underground services layout plans. The easiest way to differentiate GAS, Electric, Water, Foul Drain, Surface Drain, Combined Drain, Comms et. etc. is by using letters as part of the line type. It's one thing I miss from AutoCAD LT.
I've taken to DRAWING letters, but this is time consuming and the "letters" distort on corners and curves.
BAH!