# Preset Attributes and System Fields
This section describes the TA's preset attributes and system fields. Preset attributes refer to attributes generated or acquired by TA. All preset attributes begin with "#" **and are event attributes **, and the Chinese names and meanings of these attributes have been determined. System fields refer to structural fields in data (such as #account_id, #event_time, etc.), or fields with special purposes in the database, which are often not used in the analysis model or are used indirectly.
Except for the preset **attributes** listed below, any **attribute** that starts with "#" is considered an illegal field and will not be stored in the library. Therefore, it is not recommended that you set your custom **attribute** to start with "#". All system fields cannot be used as events or user features, passed in when data is accessed.
**Please note that all preset **attribute**s except **#ipare not recommended for direct use. Only when using the client side SDK and other transmission methods at the same time, it is** recommended under the direction of TA staff only when the attributes of multi-end data need to be consistent.**
- Preset attributes
| Attribute name | Chinese name | Description |
|---|---|---|
| #ip | IP address | The user's IP address, which the TA will use to obtain the user's geographic location information |
| #country | Country area | The country or region where the user is located is generated according to the IP address |
| #country_code | Country Area Code | The country code of the country or region where the user is located (ISO 3166-1 alpha-2, that is, two uppercase English letters), generated according to the IP address |
| #province | Province | The user's province is generated according to the IP address |
| #city | City | The user's city is generated according to the IP address |
| #os_version | Operating system version | iOS 11.2.2、Android 8.0.0 等 |
| #manufacturer | Equipment manufacturer | Manufacturers of user equipment, such as Apple, vivo, etc |
| #os | Operating system | Such as Android, iOS, etc |
| #device_id | Device ID | The user's device ID, iOS take the user's IDFV or UUID, Android takes androidID |
| #screen_height | Screen height | The screen height of the user equipment, such as 1920, etc |
| #screen_width | Screen width | The screen height of the user equipment, such as 1080, etc |
| #device_model | Equipment model | The model of the user equipment, such as iPhone 8, etc |
| #app_version | App version | Version of your app |
| #bundle_id | App package name | APP package name or process name |
| # lib | SDK type | The type of SDK you access, such as Android, iOS, etc |
| #lib_version | SDK version | The version you access to the SDK |
| #network_type | Network status | Network status when uploading events, such as WIFI, 3G, 4G, etc |
| #carrier | Network Operator | Network operators of user equipment, such as China Mobile, China Telecom, etc |
| #browser | Browser Type | The browser type used by the user, such as Chrome, Firefox, etc |
| #browser_version | Browser version | Version of the browser used by the user, such as Chrome 61.0, Firefox 57.0, etc |
| #duration | Event duration | The length of time recorded using the timing function, in seconds |
| #url | Page address | Address of the current page |
| #url_path | Page path | The path to the current page |
| #referrer | Forward address | The address of the page before the jump |
| #referrer_host | Forward path | The path to the page before the jump |
| #title | Page Title | Title of the current page |
| #screen_name | Page name | Automatically collect the name of the page used in the event |
| #element_id | Element ID | Automatically collect the ID of the control used in the event |
| #element_type | Element type | Automatically collects the type of control used in the event |
| #resume_from_background | Whether to wake up from the background | Automatically capture events used, whether the application wakes up from the background, Boolean type |
| #element_selector | Element selector | Automatically collects the viewPath used by the control in the event |
| #element_position | Element position | Automatically collects the location information of the control used in the event |
| #element_content | Element content | Automatically captures content on controls, used in events |
| #scene | Scene value | The incoming scene value when the WeChat Mini Program starts |
| #mp_platform | Mini Program Platform | Identify the platform where the application is located |
| #app_crashed_reason | Abnormal information | Automatically collect stack information used in events to record APP crashes |
| #zone_offset | Time zone offset | The number of hours the data time is offset from UTC time |
| #system_language | System language | The system language of the user equipment (ISO 639-1, that is, two lowercase English letters), such as zh, en, etc |
- System fields in the transaction table
| Field name | Chinese name | Description |
|---|---|---|
| $part_event | Event partition field | Event partition field, taken from #event_name, which is the event name |
| $part_date | Date partition field | Date partition field, taken from #event_time, which is the date the event occurred |
| #app_id | app_id | Project's APP ID |
| #user_id | User unique ID | The unique user identity of the user in the system |
| #account_id | Account ID | Account ID, equivalent to #account_id in the data |
| #distinct_id | Visitor ID | Visitor ID, equivalent to #distinct_id |
| #event_name | Event type | Event type, equivalent to the #event_name field in the data |
| #event_time | Event time | Event time, equivalent to the #time field in the data |
| #server_time | Server level time | Time when data is received at the server level |
- System fields in the user table
| Field name | Chinese name | Description |
|---|---|---|
| #user_id | User unique ID | The unique user identity of the user in the system |
| #account_id | Account ID | Account ID, equivalent to #account_id in the data |
| #distinct_id | Visitor ID | Visitor ID, equivalent to #distinct_id |
| #active_time | Time of activation | When the user's first data (including event and user feature data) is stored, the time of the data #time field |
| #reg_time | Registration time | When the user's first data containing the account ID (including event and user feature data) is stored, the time of the data #time field |
| #update_time | Update time | The time of the last user data received in the #time field |
| #user_operation | User operation type | The operation type of the last user data received (i.e., the #type field) |
| #server_time | Server level time | Server time of last user data received |