Today, I spent a handful of hours tracking down the root cause behind the message "The column name that you entered is already in use or reserved. Choose another name."
The column in question could be created, deleted and re-created in another environment, so I knew it wasn’t a reserved name. However, I simply couldn’t find the column anywhere via the standard SharePoint user interface at any site in the site collection.
I posted to MSDN forums here and the indomitable Andrew Woodward pointed me in the direction of the underlying object model data.
I went off to codeplex to find some tools that would help me peer into the underlying OM data and help me locate the trouble.
I tried several tools and they were very cool and interesting but in the end, the UI wasn’t good enough for my purpose. I’m not criticizing them by any means, but clearly the tool-makers didn’t have my problem in mind when they created their UI :). Most people seem to be investing a fair amount of time and effort in creating workstation / client applications that provide tree views, right-click context menus and so forth. These are nice and all, but it’s a lot of work to create a top-of-the-line user experience that is also very flexible.
I really needed an answer to this problem. It occurred to me that if I could get all of the site columns in the site collection into a custom list, I could filter, sort and create views that would help me find this supposedly existing column (which it did, BTW). I went ahead and did that and an hour or two later, had all my site columns loaded into a custom list with grouping, sorting and so forth. I found my answer five minutes later.
If and when I successfully take over the world, I think I will decree that all SharePoint tools providers must seriously consider surfacing their object model data in a custom list. That way, I have the power to search any way I want (constrained, of course, by standard sharepoint features).