The strange creature was unclassifiable.

The unclassifiableness of the artwork made it difficult to categorize.

The document is still unclassified.

The document is currently unclassified.

She danced unclassifiably across the stage.

The unclassifiability of the artwork makes it unique and intriguing.

The government is unclassifying the documents.

The government unclassifies the documents.

The government decided to unclassify the confidential documents.