The Waste toner box (WTB) state of Empty, Almost Full, Full is checked/triggered every time the printer starts, wakes up or a cover is closed. Therefore a KFS notification for Waste toner box will trigger for ever time this occurs.
Please see below list for WTB codes to order with a Black (K) Toner Kit (TK) when a replacement black toner is required
For high utilisation/consumption of Cyan, Magenta or Yellow send a WTB - this will be per customer/device
For the TASKalfa **52/3ci colour devices the Black TK becomes the WTB
Please see below list for WT codes to order with a TK (Black)
This list is not exhaustive - check Datasheets