# Replies

When a contact replies to an SMS, Dripcel automatically captures and categorises the response. Replies are used to update opt-in/opt-out status, trigger hooks, and improve segmentation.


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## Reply Types

A reply will be categorised into one of three types:

* **Opt-in** – If the reply contains the word **yes** (in any case: `yes`, `YES`, `Yes`).
* **Opt-out** – If the reply contains any of these words (case-insensitive):
  * `stop`, `delete`, `remove`, `no`, `opt-out`, `out`
* **Unknown** – If the reply does not match either of the above rules.

> 
:::info
> **Note:** If the campaign has hooks configured, the reply will also trigger the associated hook actions.
>
> :::


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## Custom Reply Words

Dripcel allows you to define **Custom Reply Words** to expand the default opt-in detection. This ensures that campaign-specific responses or common misspellings are still recognised correctly.

* **Default Opt-in Rule:** Only the word **yes** is treated as an opt-in.
* **Custom Words:** Add your own words to count as opt-ins.
  * 
:::info
    Example: `callme`, `yed` (common typo for “yes”).

    :::

### Rules for Custom Words

* Case-insensitive – All words are transformed to lowercase.
* Duplicate entries – Automatically removed.
* Campaign-specific – Add words relevant to your messaging or audience.


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## Example

* Contact replies: **"Yes please"** → Categorised as **Opt-in**.
* Contact replies: **"Stop sending me this"** → Categorised as **Opt-out**.
* Contact replies: **"CallMe"** (if `callme` is set as a custom opt-in word) → Categorised as **Opt-in**.
* Contact replies: **"Maybe later"** → Categorised as **Unknown**.