> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# OperatorType

> Comparison operators for filter rules.

The text operators (`contains`, `begins_with`, `ends_with`, and their
`not_` forms) ignore letter case. `is_empty` matches an empty string,
not a missing value. In span filters, `is_null` and `is_not_null` work
only on `Evaluator::` and `Annotation::` outputs.

Which operators a field accepts depends on its data type. The server
rejects an incompatible pair and lists the allowed operators in the error.

**Values:**

* `ANY` = `"any"` - Match when an array field contains `value`. Not supported in span filters.
* `EQUAL` = `"equal"` - Field equals `value`.
* `NOT_EQUAL` = `"not_equal"` - Field does not equal `value`.
* `IN` = `"in"` - Field equals one of the values in a list.
* `NOT_IN` = `"not_in"` - Field equals none of the values in a list.
* `LESS` = `"less"` - Field is less than `value`.
* `LESS_OR_EQUAL` = `"less_or_equal"` - Field is less than or equal to `value`.
* `GREATER` = `"greater"` - Field is greater than `value`.
* `GREATER_OR_EQUAL` = `"greater_or_equal"` - Field is greater than or equal to `value`.
* `BETWEEN` = `"between"` - Field is within a `[low, high]` range, inclusive of both ends.
* `NOT_BETWEEN` = `"not_between"` - Field is outside a `[low, high]` range.
* `BEGINS_WITH` = `"begins_with"` - Text field starts with `value`.
* `NOT_BEGINS_WITH` = `"not_begins_with"` - Text field does not start with `value`.
* `CONTAINS` = `"contains"` - Text field contains `value`.
* `NOT_CONTAINS` = `"not_contains"` - Text field does not contain `value`.
* `ENDS_WITH` = `"ends_with"` - Text field ends with `value`.
* `NOT_ENDS_WITH` = `"not_ends_with"` - Text field does not end with `value`.
* `IS_EMPTY` = `"is_empty"` - Field is an empty string.
* `IS_NOT_EMPTY` = `"is_not_empty"` - Field is not an empty string.
* `IS_NULL` = `"is_null"` - Field has no value. In span filters, only for `Evaluator::` and `Annotation::` outputs.
* `IS_NOT_NULL` = `"is_not_null"` - Field has a value. In span filters, only for `Evaluator::` and `Annotation::` outputs.