Would someone be kind enough to explain about Hypos, please? I have read that some are not compatible with another. Whats the deal?

I have a 100% het Bell line Yellow Ghost (Thanks Jas!) that I am looking to breed next year but I and not "getting" the gist of the hypo lines.

Anyone know where I can get a male that would be compatible?

Sorry if this sounds scatterbrained...been one of those days