There are lots of commands in AutoCAD that starts with letter X, commands that AutoCAD users frequently use or never been used at all . Personally some of these “X” commands that I am talking about got a chance to be use by me, but then some I never got a chance to try at all.

These commands are:

• XREF - (EXTERNALREFERENCE) A command that you’ll use if you’re trying to insert a drawing reference within a drawing. My most frequently use “x” command.
• XCLIP - A command that defines an xref or block clipping boundary, in other words if you want to insert only a certain portion of an xref drawing you can use the Xclip command.
• XBIND - A command that binds one or more definition of named objects in an xref to the current drawing.
• XATTACH - A command that attaches an external reference in the drawing. I think this command is part of XREF command.
• XEDGES - A command that creates wireframe geometry by extracting edges from a 3D solid or surface.
• XLINE - A command that creates line that extend to infinity in one or both directions, it is also known as construction line and can be used as a reference for creating objects.
• XOPEN - A command that opens a  selected drawing reference (xref files) in quickest way and its open in a new window.
• XPLODE - A command that breaks a compound object into its component object. typically you’ll use this command  when you want to separate one object within a block.