# Data Item Registration and Inquiry (DataItemList)

## Data Item List Registration

Register the list of data items in the dataset. This item list is used to define and manage each item in the dataset. Below are the necessary items and descriptions for data item registration:

### Name (Name)

- **Description:** Specifies the name of the dataset item.
- **Purpose:** The name of the data item is used to identify the item.

### Description (Description)

- **Description:** Enter the description of the dataset item.
- **Purpose:** Adding a description to the data item helps understand the meaning and role of the data item.

### Active (Active)

- **Description:** Sets whether it is in use.
- **Purpose:** Data items can be activated or deactivated to control their use within the dataset.

### Hidden (Hidden)

- **Description:** Sets whether to show to users when used in reports or secondary processed data.
- **Purpose:** Hiding data items can make them less noticeable in reports and other documents.

### Group (Group)

- **Description:** Assigns a group to data items with the same group field so that they can be displayed as a subgroup in table format within the entire dataset.
- **Purpose:** Grouping related data items improves the visibility of the data and defines their association. Typically, these data items have a quota of more than one, and it is meaningful to set the same quota value.

### Tag Name (Tag Name)

- **Description:** Sets the object key.
- **Purpose:** Specifies the key name used when representing data items as subfields in a JSON format object.

### Type (Type)

- **Description:** Selects the data type for the dataset item value.
- **Purpose:** Specifies the data type of the data item to define the format of the data.
  - Possible types:
    - Number (Number)
    - Text (Text)
    - Select (Select)
    - Boolean (Boolean)
    - File (File)

### Select Options (Select Options)

- **Description:** For select type, additionally sets name and value pairs.
- **Purpose:** Specifies the possible normal value options for select type data items.

### Statistical Functions (Statistical Functions)

- **Description:** Sets the statistical function to be applied to the item when periodically collecting period data to create summary records.
- **Purpose:** Used to collect statistical information for the data item.
  - Possible statistical functions:
    - Sum (Sum)
    - Mean (Mean)
    - Standard Deviation (Standard Deviation)
    - Variance (Variance)
    - Minimum (Minimum)
    - Maximum (Maximum)
    - Range (Range)
    - Median (Median)
    - Mode (Mode)

### Unit (Unit)

- **Description:** Sets the input unit. (e.g., kg, cm)
- **Purpose:** Specifies the unit of the data item value to manage the data in a consistent format.

### Sample Count (Sample Count)

- **Description:** Sets how many item values will be received.
- **Purpose:** Specifies the sample count of the data item value to determine the number of samples needed for data input.

### Specification (Specification)

- **Description:** When specifications are defined, deviating values are added as OOC (Out of Control) data.

- **Purpose:** Sets specifications for the data item to detect and manage deviating values.
  - Possible specifications:
    - CCP (Critical Control Point Data Spec): Critical control point data specification
    - QC (Quality Control Data Spec): Quality control data specification
    - SPC (Statistical Process Control Data Spec): Statistical process control data specification (not yet supported)

These items can be used to define data items and set and manage the associations between data items within the dataset.