&s3=641087d2d4d99500019e3822&s1=10 Now

: This is a numerical value (10). In tracking systems, s1 often refers to a "Sub ID" or a specific source/channel identifier.

This format defines exactly what each piece of the string represents in a data context. &s3=641087d2d4d99500019e3822&s1=10 &s3=641087d2d4d99500019e3822&s1=10

: This is a unique identifier. Based on its 24-character hexadecimal format, it is likely a MongoDB ObjectID . It identifies a specific record in a database (e.g., a user ID, a campaign ID, or a session ID). : This is a numerical value (10)

In a functional environment, these parameters cannot stand alone; they must follow a ? after a base URL. https://service.com Summary Recommendation a user ID