ConfigurationElement—Combination of Attributes?

Question

Say I have defined a custom AdapterElement : ConfigurationElement with properties Type, Name and Version. Since Name and Version uniquelly identifies the Type property, I would like to enforce the configuration file to have one of the following structures:

<adapter type="TypeOfAdapter"/>
<adapter name="NameOfAdapter" version="VersionOfAdapter"/>

I could easily mark those three properties with IsRequired = false and let users specify the combination the want. However, the following combinations are not valid and I would like to forbid them:

<adapter type="TypeOfAdapter" version="VersionOfAdapter"/>
<adapter type="TypeOfAdapter" name="NameOfAdapter"/>

Is there any easy way of achieving this?