NAICS 33421 (five-digit) and 334210 (six-digit) cover the same scope — telephone apparatus manufacturing — because there is only one six-digit industry within this five-digit group. Trade statistics published at either level reflect the same underlying data, so analysts can use either code interchangeably when querying Census Bureau trade databases.

Multifunction communications devices must be classified under the HTS heading that corresponds to their principal function, as determined by the General Rules of Interpretation and relevant chapter notes. A device marketed primarily as a telephone but capable of video conferencing may still fall under telephone apparatus headings, but a device whose primary function is data routing would likely classify elsewhere. Consulting a licensed customs broker is advisable for borderline cases.