---
title: SystemUser
summary: API reference for SystemUser.
status: draft
owner: SAIF.Core documentation team
last_reviewed: 2026-09-24
library: SAIF.Data
reference_type: package
---

# SystemUser

Domain entity representing System user data within the system users area of the claims/policy domain, mapped for NHibernate persistence.*

## Purpose
- Models system user data used by the system users area of this library.*
- Inherits shared identity/lifecycle behavior from `EntityBase`.

## Context
- Namespace: `SAIF.Data.Model.SystemUsers`
- Assembly/package: `SAIF.Data`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| UserName | `string UserName { get; set; }` | Value of user name exposed by this type.* |
| LastName | `string LastName { get; set; }` | Value of last name exposed by this type.* |
| FirstName | `string FirstName { get; set; }` | Value of first name exposed by this type.* |
| MiddleName | `string MiddleName { get; set; }` | Value of middle name exposed by this type.* |
| PositionTitle | `string PositionTitle { get; set; }` | Value of position title exposed by this type.* |
| PhoneNumber | `string PhoneNumber { get; set; }` | Value of phone number exposed by this type.* |
| PhoneExtensionNumber | `string PhoneExtensionNumber { get; set; }` | Value of phone extension number exposed by this type.* |
| EmailAddress | `string EmailAddress { get; set; }` | Value of email address exposed by this type.* |
| SystemUserType | `SystemUserType SystemUserType { get; set; }` | Reference to the associated `SystemUserType` record.* |
| UpdateDate | `DateTime? UpdateDate { get; set; }` | Date/time value for update date.* |
| UpdateUser | `string UpdateUser { get; set; }` | Value of update user exposed by this type.* |
| UpdateNumber | `int UpdateNumber { get; set; }` | Value of update number exposed by this type.* |

## Behavioral notes
- Properties are typically declared `virtual` to support NHibernate lazy-loading proxies (see the corresponding mapping file under `Data/SAIF.Data.NHibernate`).*

## Constraints and usage notes
- No additional usage constraints beyond standard NHibernate entity/DTO conventions could be confirmed from static analysis.**

> **Note:** Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts. Statements marked with ** could not be confirmed; treat as unknown until verified.

## Sources
- `Data/SAIF.Data/Model/SystemUsers/SystemUser.cs`