This finds .txt files only on government domains.

The 2021 modifier locks the search to content either or last indexed in 2021 (depending on the search engine’s date range tools). In the context of cybersecurity and data analysis, 2021 is a significant year—it saw major data breaches, the rise of remote work vulnerabilities, and a massive increase in exposed .txt files on misconfigured servers.

This limits the results to more recent data, specifically looking for information leaked or uploaded during that calendar year. What is the Goal?

Google sometimes ignores negative operators if they are too common. Use quotes around the negative term: -“gmail.com” or use the intext: operator.