A unique numeric or alphanumeric code assigned to an account by the platform's internal system, often sequential or timestamp-based. Internal identifiers can reveal registration order, approximate registration date, and help enumerate accounts.
### Related weaknesses
- [[SOWEL-1. Having and Filling Account]]
### Related techniques
- [[SOTL-1.4. Analyze Internal Identifiers]]
- [[SOTL-1.6. Iterate Through Numeric Identifiers]]