Reserved Parameters

Parameters have special meanings that may be different depending on their context, as outlined in the following table.

Parameter	Descriptor Element	XSL	HTTP/SOAP
`_self`	N/A	Set to the URL of the Descriptor being invoked	Set to the URL of the Descriptor to invoke
`_target`	Set to the URL of the Descriptor to invoke	N/A	N/A
`_source`	Set to the URL of the current Descriptor being invoked	N/A	N/A
`_cacheClear`	see HTTP/SOAP	see HTTP/SOAP	For Development Only If set to any value, all cached Descriptors are cleared. This is useful for developers when testing a Descriptor. Ordinarily, Descriptors are cached for performance reasons and do not know if they have changed unless the cache is cleared

Note - Depending on the context, some variables are set, such as _self, while others need to be set, such as _target.