DALI: How do I delete the short address from a device?
Yes it can be done. You have to send 3 forward frames

Command 257 SET DTR (binary 1010 0011 1111 1111)
which has value 0xFF (sets DTR to 0xFF which is MASK)

Command 128 STORE DTR AS SHORT ADDRESS (binary YAAA AAA1 1000 0000), repeated twice within 100ms.

Command 257 is not addressed, so will be processed by all the gear on the bus. The way you apply it to only some of the gear is by setting the address in Command 128. So you can delete the short address in all gear (broadcast), only those in a particular group (group addressed) or only those/that one with a short address. Many commands use DTR this way, so you should not rely on a previously set DTR value before sending your configuration command; the DTR is likely to change frequently.

Y=1 means group address or broadcast. 0 means A bits are short address

A bits are the binary of 0 to 63 for short address, 0-15 for group address, all 1s for broadcast.