When performing a copy/paste function, you can choose to copy across any processing into the new file. If you tick ‘processed data only’, then Casa will copy the block after processing, but will reset the processing history. This can be useful if you want to do multiple processing steps, but want to start each processing form from a ‘blank’ processing history (so you can perform processing functions, then reset without resetting, for example, an initial calibration).
In the example above, we are copying a block that has been calibrated to carbon. If we check the processing history after copying, it is empty, but the sample is STILL calibrated – because we copied the ‘processed version’ only. Now, if we want to perform processing actions such as PCA/LCF where we might want to try some parameters, then reset to tune some settings – we can reset the processing history without having to repeat the calibration each time.