Can Signup Code Be Required Only When Creating Blogs and Not For User Only Signups

Hello,

We need the signup code to only apply for blog creation and not for user signup.

Users who are just registering on subblogs of the main site should not be required to enter the signup code.

Only a user creating a blog on the main site should be required to enter the signup code.

Is this a modification (or option) that can be incorporated into the Signup Code plugin?

If so, can anyone provide the code to do so?

Interestingly, I have discovered that some subsites using WP-Members do not encounter this issue as new users registering through that plugin's interface do not encounter the signup code field when registering. That plugin seems to ignore the Signup Code requirement when active on some themes even though it is active.

Thanks,
Phil D