I think you're talking about Dagdha rashis, dagdha literally means burnt

On each tithi, some particular rashis are burnt/damaged, in whichever houses these fall, those houses and planets placed there suffer

If these fall in dusthana houses, then it's okay because less imp houses of the kundali will suffer

On most tithis, 2 rashis are dagdha, on amawasya and poornima no rashis are dagdha and on chaturdashi 4 rashis are dagdha

There's also one exception here, if the lords of the dagdha rashis are placed in those rashis then it's like a cancellation