Quantification of gene expression by in situ hybridization: finding and using the raw values

Hello,
I would like to know what the probe name used for the ISH experiments means in the Developing mouse brain atlas.
Some ISH done for the same gene at different developmental stages show different probe names. However, in some cases the sequence of the primers is the same but the probe number is not. If the primers used for the PCR were the same for generating 2 probes, the sequence of the probe should be the same, but in same cases they have a different number.
Thus, how do I know if the same probe was used for different experiments? What could be the differences between 2 probes with different probe number but generated with the same pair of primers?

Thank you for your help

Juan