Knowing this will allow me to provide a more specific answer.
Based on a search of the available information, there is no widely recognized report, database, or official file titled [1]. Download 500 userx txt
To help me narrow down what you are looking for, could you please tell me: Knowing this will allow me to provide a more specific answer
What (e.g., IT support, data analysis, security investigation) is this related to? there is no widely recognized report
did you encounter this phrase (e.g., a website, a command line, an email)?
Similar syntax is often used in security testing to enumerate or list user accounts.