## ParserBuilder.registerPrefix() method [​](/content/docs/sdk/core.parserbuilder.registerprefix#parserbuilderregisterprefix-method "Direct link to ParserBuilder.registerPrefix(/index.html) method")

**Signature:**

```typescript
registerPrefix(tokenType: string, parselet: PrefixParselet): this;
```

## Parameters [​](/content/docs/sdk/core.parserbuilder.registerprefix#parameters "Direct link to Parameters"/index.html)

| Parameter | Type | Description |
| --- | --- | --- |
| tokenType | string |  |
| parselet | [PrefixParselet](/content/docs/sdk/core.prefixparselet) |  |

**Returns:**

this

- [ParserBuilder.registerPrefix() method](/content/docs/sdk/core.parserbuilder.registerprefix#parserbuilderregisterprefix-method/index.html)
- [Parameters](/content/docs/sdk/core.parserbuilder.registerprefix#parameters/index.html)