This option enables you to turn on/off the built in cleanup functionality. TinyMCE is equipped with powerful cleanup functionality that enables you to specify what elements and attributes are allowed and how HTML contents should be generated. This option is set to true by default, but if you want to disable it you may set it to false. Notice: It's not recommended to disable this feature.
Example of usage of the cleanup option:
tinyMCE.init({
...
cleanup : true
});