Is there a bug in SharePoint that copies a custom column?

I created a custom Revision column in one of my document libraries and required data to be put into it. The document library had some documents in it and I tried uploading a file. I put the data in Name and Revision, but it gave me an error that I was mis开发者_如何学编程sing information. So I checked the columns in site settings and found 2 Revision columns that each required information and only one would be displayed when editing/entering new information. I deleted the column from that library, and I had to delete it from many other libraries as well.

It seems to only happen with libraries that have content. None of my empty libraries have this problem, only the ones with documents.

Is this a problem with SharePoint, and if so, what can I do to avoid this problem? If there is no way to avoid it, is there a way to delete all the extra cloned columns?

Thanks.

I had moved the files from one folder to another and it created a second Revision column since the two did not match. When you move items from one library to another, you should try moving the items before adding the columns because the columns will be auto generated. I had this happen to me again when I move Contacts from one list to another.