One of the most important parts of XREFs are the paths that they use to find the files. You can use Hard coded paths or relative paths. Read more about these options here.

So here are some thing you could add to your CAD Standard about creating and using XREFs.

Xref Path Names

All Reference file attachments will be saved using relative paths. Relative paths do not include the drive letter and reflect the location of the reference file as it relates to the active file.

Relative path names can be created in AutoCAD by using a shareware program called XRP. AutoCAD 2004 and beyond has a variable setting to allow for relative paths.

Reference files shall be added on a specific layer and the prefix for that layer shall be “$xref-“ followed by the reference file name. “$nref-” shall be used as a prefix when attaching nested reference files to model files.

Only use one level of nesting. Do not overuse nested reference files. Attaching a file to create a Nested XREF should only be done on Model files. Do not create nesting on Sheet files.

The lisp routine “XRP” will correct the hard coded paths to relative paths in AutoCAD 14 thru 2010. AutoCAD 2004 and beyond allows for attachments with relative paths. It must be done at the time of attachment or fixed with XRP after the fact. Get XRP – you need it.

Here are my guidelines for short key in names…

• Keep them on the left side of the keyboard – close to the left hand that usually rests on the keyboard
• Keep them key-able with one hand. Don’t make me take my other hand off the mouse.
• Keep them somehow associated with the command name or function. (an abbreviation)
• Feel free to double up on characters
• Do not use numbers in the name
• Use three characters if needed
• Use grouped letters that are close to each other on the keyboard
• Do not make me move my hand back and forth on the keyboard if you use three characters
• It is easier to move from left to right on the keyboard than the other way
• It is easier to go from top to bottom on the keyboard

By following a few tips about naming the abbreviated command you can gain even more speed by reducing the thinking and typing required.

I have used this program forever. And it is GREAT!

XRP – generate relative paths for XREFs – Xrp2004.lsp – created by Mark McDonough

From the author – “I wrote this for AutoCAD R14 (7 years ago) and I keep waiting for AutoCAD to fully embrace “Xref Relative Pathing”. But even with AutoCAD R2007, one still needs a utility to convert full XREF paths into relative paths. AutoCAD 2004 was the first release that allowed specifying a relative path when first attaching an XREF, it still does not allow automatic conversion of existing full XREF paths into relative paths. Nor is there any support for relative pathing for IMAGES. XRP makes the conversion of full XREF & IMAGE paths into relative paths easy. For AutoCAD R14 – R2006 (not yet tested in R2007, but feel free to give it a try). After loading the lisp file, the command name is XRP.”

See more code at http://www.caddmanager.com/Programming.html

Here are some good places to start your education in AutoLISP.

Basic LISP from the Lazy Drafter

LISP Primer – by Colin Allen and Maneesh Dhagat

AutoLISP Tutorials – by acadsolutions

Introduction to AutoLISP Programming by Ralph Grabowski

Basic AutoLisp Programming by David Hoeksta – old but fairly good for beginners

The ones that have served so well have been those small little routines that have fixed something or reduced the number of clicks that I have to do to get something done.

Here are some places to look for AutoLISP code…

http://new.cadalyst.com/code/ – the Cadalyst extensive library

http://www.jefferypsanders.com/autolisp.html – Free stuff

http://home.pacifier.com/~nemi/ – Better than Nothing AutoLisp – has some annoying popups.

http://www.autolisp.com/forum/ – Nice forum of stuff

http://www.afralisp.net/ – Afralisp

And of course the forums on AUGI.com!

You also could start reading up and create your own. It is easy and it is fun.