The multi-line entry field control window procedure responds to this message by setting the window parameters indicated by the fsStatus parameter of the WNDPARAMS data structure, identified by the pwndparams parameter.

If the MLE text is to be set by this message, it is assumed to be in CF_TEXT format (see MLM_FORMAT) and all existing text is deleted before the new text is inserted. Note that a Control Data structure can be associated with the window parameters, in which case any field in that structure can cause a change to the MLE.