Note: For your future reference, the forum can also searched to find topic in any forum. Select the Search link in the upper right hand corner. Enter the Search words and be sure to select Search All Open Forums in the Search Forum/Archive list box.

The best solution is to change the entity name to from one spelling to the other and then back again.
Select File | Change Entity Name. On the Entity Name, change it from the "&" to "and" so it is exactly like the other name. Select Ok and to change the entity name. This will combine it with the entity name that already exist. Now only 2 entity names will be used.

Next select File | Change Entity Name to change it back to the original name. Now the name will be spelled the way you want it and only 2 entities will be used.

Note: If you have data files from previous years with different spelling then you will need to change them also. Otherwise it will add them as a new entity when the previous years data files are opened.

Also look at the other topic about deleting entities at Deleting entities