The book lists كَيْتَ and ذَيْتَ as stand-ins for unspecified speech or events.
Added usage: «حَدَثَ كَيْتَ وَذَيْتَ» — Such-and-such happened.
They do not request a numerical value, so they should not be treated like kam governing a numerical tamyīz.
The added phrase is a teaching illustration, not a quotation from the source.