: This is the production code (also known as a "JAV code"). "NHDT" is the label, and "511" is the specific release number in that series.

While the "NHTD" acronym commonly refers to the Medicaid Waiver Program in professional medical contexts, the specific format of your query (Label-Code-Format@Uploader) is almost exclusively used for cataloging Japanese Adult Video content.

The term is frequently found in file-sharing contexts, such as:

: Users often search for this specific string to find high-quality versions of the production.

: Indicates the digital video container format used for this specific copy of the file.