Find XCliped Xrefs — Kent Cooper — This routine finds any xrefs in the current space that have been clipped with the XClip command, and draws a heavy red polyline around the clipping boundary of each for easy visual identification.

Orient Lines to Slope in the Same Direction — Kent Cooper — If you create lines in AutoCAD with different z elevations on each end and you use directional linetypes, such as a linetype with an arrow, you can change the linetype orientation so that the arrowheads are either all pointing “uphill” or “downhill,” based on the z elevations on the line.    

Convert 3D Faces To Polylines — Kent Cooper — This routine is similar to CAD Tip No. 4402, also from Kent Cooper, except it converts 3D faces to 3D polylines. All edges, regardless of their visibility status in the 3D face, will be created using this routine.

Layer Color, Lineweight, and Plot Style Utilities — Michael Partenheimer — Since the National CAD Standard (NCS) no longer associates a color to a plot thickness, these three separate but related LISP routines were designed to help AutoCAD users with this transition. Users can set the lineweight of each layer based on the layer color or layer plot styles, or set layer colors based on the lineweight of that layer.