# Custom column annotation

Today, we have already covered the `AutoIncrementId` annotation. It is a `column annotation`. However, you can also create your own annotations with custom behavior:

```typescript
export const BooleanColumn = ColumnAnnotationFabric.create({
    type: ColumnType.BOOLEAN,
    notNull: true
})
```

Or this:

```typescript
export const BooleanColumn = ColumnAnnotationFabric.create(DefaultColumn.BOOLEAN)
```

It is worth noting that if you create annotations as constants rather than functions (including arrow functions), you don't need to add parentheses when using them. However, if your annotation accepts a value (even an optional one), you must use it with parentheses after the name.

### [Next >](Information%20schema.md)