I am reprinting a post from last August that deals with ArcIMS projection metadata.  If you are an ArcIMS server administrator and you don't set your projection in your map service you are really doing yourself and others a disservice.  The numbers have gotten better since then, but still only 36.5% of the map services have a valid projection. 


From 22 August 2005:

One of the most disturbing things I have found out from building Mapdex is the lack of proper projection information set for mapservices.  It turns out that about 56.5% of mapservices lack a projection or cannot be assumed to be geographic.  Only 31.3% of mapservices have a valid projection while 12.2% can be assumed geographic. 

What happens if you don't have a valid projection set?

• You cannot use your mapservice within ArcMap with other data layers outside of your projection;
• All of your data layers in your mapservice have to be in the same projection;
• You cannot publish your mapservice to the National Map or to GOS;
• Other groups cannot use the valuable data within your mapservice within their data and/or applications;
• Your mapservice cannot be searched spatially within Mapdex or other map search engines.

There is a nice article in ArcUser about georeferencing ArcIMS services.  I encourage you to check it out.

http://www.esri.com/news/arcuser/0205/files/georef_arcims.pdf

Cheers,

Jeremy