---
metadata:
  - name: generator
    content: Diplodoc Platform v5.52.0
alternate:
  - https://catboost.ai/docs/en/concepts/input-data_custom-borders.md
  - href: en/concepts/input-data_custom-borders.md
    type: text/markdown
    title: Markdown version
  - href: ../llms.txt
    type: text/markdown
    title: llms.txt
---
> **Documentation Index:** Fetch the complete configuration index at https://catboost.ai/docs/en/llms.txt

# Custom quantization borders and missing value modes

#### Contains

Custom quantization borders and the method for processing missing values for the dataset numerical features.

#### Format

- Each line contains information regarding a single border and optionally the missing values mode settings for the corresponding feature.
- Different missing values mode settings can not be specified for a single feature. The value either has to be set only on one line or should be the same on different lines that contain information regarding a single feature.
- Supported missing values modes:

  <!-- source: en/_includes/work_src/reusage-missing-values/mv-processing-methods.md -->
  - "Forbidden" — Missing values are not supported, their presence is interpreted as an error.
  - "Min" — Missing values are processed as the minimum value (less than all other values) for the feature. It is guaranteed that a split that separates missing values from all other values is considered when selecting trees.
  - "Max" — Missing values are processed as the maximum value (greater than all other values) for the feature. It is guaranteed that a split that separates missing values from all other values is considered when selecting trees.
  <!-- endsource: en/_includes/work_src/reusage-missing-values/mv-processing-methods.md -->

- The missing values mode for the feature is defined by the value of the `--nan-mode` (`nan_mode`) training parameter if not specified in this file.
- Format of a single line:
    ```
    <zero-based feature ID><\t><border value><\t><missing values mode (optional)>
    ```


#### Example
The following description contains two borders for features indexed 0 and 2 and missing values settings for each of these features:
```
0<\t>0.25<\t>Forbidden
0<\t>0.75<\t>Forbidden
2<\t>0.3
2<\t>0.85<\t>Max
```