Duplicate program class key in registry

I discovered a duplicate program class key in HKCR for
Microsoft.ITIR.WordWheelBuild.5.4. The first key has a default value of
"Microsoft Infotech ITIR Word Wheel Build" and the second is
"Microsoft.ITIR.WordWheelBuild.5.4". They both have the same CLSID of
{3E6C7FFD-743D-4265-8E3D-0D7EA889DFDB} which is itircl54.dll. Other systems I
have checked have only the first key. The questions I have are:

1. Shouldn't program class keys must be unique?

2. What is the possible affect of deleting second (assumed to be duplicate)
key?

3. What is WordWheelBuild 5.4?