Yii’s default validator Aliases

Below is the complete list of predefined validator aliases:

• boolean: alias of CBooleanValidator, ensuring the attribute has a value that is either CBooleanValidator::trueValue or CBooleanValidator::falseValue.

• captcha: alias of CCaptchaValidator, ensuring the attribute is equal to the verification code displayed in a CAPTCHA.

• compare: alias of CCompareValidator, ensuring the attribute is equal to another attribute or constant.

• email: alias of CEmailValidator, ensuring the attribute is a valid email address.

• date: alias of CDateValidator, ensuring the attribute represents a valid date, time, or datetime value.

• default: alias of CDefaultValueValidator, assigning a default value to the specified attributes.

• exist: alias of CExistValidator, ensuring the attribute value can be found in the specified table column.

• file: alias of CFileValidator, ensuring the attribute contains the name of an uploaded file.

• filter: alias of CFilterValidator, transforming the attribute with a filter.

• in: alias of CRangeValidator, ensuring the data is among a pre-specified list of values.

• length: alias of CStringValidator, ensuring the length of the data is within certain range.

• match: alias of CRegularExpressionValidator, ensuring the data matches a regular expression.

• numerical: alias of CNumberValidator, ensuring the data is a valid number.

• required: alias of CRequiredValidator, ensuring the attribute is not empty.

• type: alias of CTypeValidator, ensuring the attribute is of specific data type.

• unique: alias of CUniqueValidator, ensuring the data is unique in a database table column.

• url: alias of CUrlValidator, ensuring the data is a valid URL.

Source:  http://www.yiiframework.com/doc/guide/1.1/en/form.model