grammar - Can 'default' be an adverb?

Consider the following sentence:

Whenever possible, default and explicitly mapped names are honored as written.

It seems to me that default and explicitly both talk about how the names are mapped, and thus default would also be an adverb, but I don't see default listed as an adverb in the dictionary.

But they could also be nouns when written as thus:

Whenever possible, default and explicit mapped names are honored as written.

What would be the clearest way to write this and can 'default' be an adverb as shown above.

Another pass at the sentence might read:

Whenever possible, default mapped names and explicitly mapped names are honored as written.

Answer

Perhaps this works?

Whenever possible, explicit and default mappings are honored as written.