PDF Creator Pilot supports the following line join styles:

Name	Description	Value
ljsMiter	The outer edges of the strokes for the two segments are extended until they meet at an angle, as in a picture frame. If the segments meet at too sharp an angle, as defined by the miter limit parameter of SetMiterLimit, a bevel join is used instead.	0
ljsRound	A circle, with a diameter equal to the line width is drawn around the point where the two segments meet. The circle is filled in, producing a rounded corner.	1
ljsBevel	The two segments are finished with butt caps using SetLineCap. The resulting notch beyond the ends of the segments is filled with a triangle.	2